Bjorn Lomborg on the Costs and Benefits of Attacking Climate Change
Jun 10 2019

2019/06/climate-change.jpg Bjorn Lomborg, President of the Copenhagen Consensus Center, talks about the costs and benefits of attacking climate change with EconTalk host Russ Roberts. Lomborg argues that we should always be aware of tradeoffs and effectiveness when assessing policies to reduce global warming. He advocates for realistic solutions that consider the potential to improve human life in other ways. He is skeptical of the potential to move away from fossil fuels and argues that geo-engineering and adaptation may be the most effective ways to cope with climate change.

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Explore audio transcript, further reading that will help you delve deeper into this week’s episode, and vigorous conversations in the form of our comments section below.


Jun 10 2019 at 12:55pm

I found this discussion frustrating.

Why didn’t Russ challenge the assumption that proactively cutting climate emissions is bad for the short term economy? It would be bad for the current energy establishment, but not bad for the economy. Russ is good at challenging assumptions but lets this one slide all the time.

Brad Hobbs
Jun 10 2019 at 8:17pm

Conner, I’m not following your argument. Are you saying that doing serious damage, short term, to the current energy establishment, would not impact you or me or the economy?  I’m thinking about say a move to zero CO2 emissions.  That would conceivably put the oil companies out of business, with resulting non trivial impacts on the stock market which impacts my life insurance, the bank that pays me interest, the broker that holds my retirement account.  It would also make my three cars, boat, jet ski, lawn mower, whole house generator, my furnace, oven, gas grill, etc. either seriously more expensive to operate, or require me to trash them and start over.  I suppose I would need to invest a hundred grand in solar, and if I want my AC and lights to work at night, I need to spend a lot on batteries.  I also need excess capacity, in case it is cloudy outside like it has been for the last 7 days. effectively, I need a system that’s multiple times larger… That would be a huge cost to me an to you, along with the rest of us… I would think that the impact on the economy would be huge. As devices that already serve us become useless or much more expensive, it would have the same effect as having a huge portion of the wealth of the world simply go away.

Peter Parisi
Jun 10 2019 at 12:55pm

I hate to criticize and excellent program (to which I listen weekly, usually on the day that it becomes available). Nevertheless, it seems to me that thirteen years of producing the show has led to a certain carelessness in Dr. Robert’s responses to his guests. For example, on many occasions, he “pushes back,” as he puts it, against the claims of his guests. This is entirely proper and is what listeners expect a good interviewer to do (and Roberts is certainly a good interviewer). Sometimes, however, he will begin a simple contradiction of a claim made by a guest with the phrase “It is not obvious to me that X,” without giving grounds for his contradiction. However, the phrase “It is not obvious to me that X” is no different from the phrase “You are wrong to say that X.” It may be more polite, but it is not meaningfully different. What I would expect to hear after such a phrase is at least one reason why “it is not obvious that X.” Sometimes, no such reason follows. This happens frequently enough that I feel it necessary to comment. An example occurs at 47:17, when Dr. Roberts uses the, as he admits, impossible thought experiment of giving free food to impoverished people as a counterargument against Lomborg’s suggestion that improving nutrition would have enormous positive economic outcomes. In fact, Roberts’ thought experiment obscures, or at least misconstrues, Lomborg’s point: improving the food supply by increasing the nutritional content of wheat and other staples will certainly improve the ability of children to learn at the same rate as children in developed economies, with demonstrably positive results. Roberts’ argument–that damage might be done to local economies–is an excellent argument against the fictitious thought experiment he has introduced (ie. giving away free food), but no argument at all against improving the nutritional content of wheat. Certainly, there will be unintended consequences, but they would likely be other than the damage that he suggests.

The mention of unintended consequences brings me to another quibble. At about 51:20, in response to another of Lomborg’s claims, Roberts “taps into his inner Nasim Taleb and points out that fortifying things, especially through GMO, may have unintended consequences down the road, but . . . hard to know.” It is, however, trivial to claim that an act will have unintended consequences. All acts have consequences of one sort or another, many of them unintended. And, of course, the addition that these consequences are “hard to know” is what defines unintended consequences. Thankfully, Lomborg jumps in to point out that fortification through GMO’s was not what he was talking about. Dr. Roberts had simply misunderstood the point he was trying to make. But it needs also to be said that nearly any meaningful action taken to address any problem will have unintended consequences. This is not an argument against taking any specific action, nor is it an argument against taking any action at all. Certainly, it is reason for caution, but that is not really how Roberts presented the objection.

I suspect that Dr. Roberts’ responses in these situations arise from his deep suspicion of top-down approaches to dealing with problems. I share both this suspicion and its depth. Nevertheless, an argument has to be based on more than just one’s native distaste for an idea.

David Gossett
Jun 12 2019 at 4:37pm

Russ can’t win no matter what he does! If he states his position in any detail, he gets dinged for talking too much and not allowing the guest to speak. If he asks for clarification without going into more detail, he is dinged for not elaborating on his position.

I think Russ has the right idea. Let the guest talk. Ask for guest to expand on a thought, but don’t debate the guest. Russ is saying guest’s message is not obvious enough. This triggers the guest that more persuasion may be needed for his Econtalk audience. Russ is playing the every-man, representing his listeners and trying to channel them… Russ says this all the time.

We cast stones, but let’s take a step back and appreciate that Russ is doing this on the fly. He is trying to participate in the guests’ expertise and life work. He can’t be expert enough in every episode to push back with details.

I always get this feeling that guests love Russ more than we do… they love the back and forth, the challenges, the depth of the discussion, not getting off too easy… that Russ is not just a yes man, but making them work for the interview. I think Taleb takes the first 5 minutes of every visit to hit this point home. Taleb is telling all of us just what a gift we have in Russ.

Jun 17 2019 at 5:26pm

You are absolutely right, and I withdraw my criticism of a very minor flaw in an otherwise excellent installment.

John H Adams
Jun 10 2019 at 3:19pm

This presumes that this is a problem that needs solving. Lomborg’s solution does nothing to control the global economy which is the hidden agenda of global warming.

Jonathan de Ruiter
Jun 10 2019 at 3:45pm

Fantastic discussion as always, this guest has inspired me to look deeper into the discussion around our attempts to curb climate change — especially via cutting carbon emissions.

However, I feel confused about his message on how ‘we’ should feel about the importance of reducing carbon emissions [henceforth as RCE]. I was trying to identify why, and I think it’s because I expected Russ to ask an explicit question at some point something like: “are you saying we shouldn’t focus very much at all on RCE? Or just that it should be treated with the same importance as any other threat to life on Earth [bio-terrorism/asteroid etc]?”

Maybe I missed something, or the way they were talking about it wasn’t explicit enough for me… Was Lomborg admitting that RCE is definitely something we should direct resources to when he was talking about how we should focus our efforts on more efficient alternatives [as opposed to solar panels and wind turbines I think were his examples of not-very-efficient].

I want to make sure I understood his arguments, because the conversation seemed to be saying that we should not worry very much or try and ‘do’ much to RCE — that based on the best current evidence we have, it won’t be a very costly or serious problem for humanity/life on Earth.

So with that being the message, I found it hard to wrap my mind around how much he/they both think we should care about RCE/negative effects of climate change. Should we not worry about rising global/sea temperatures much at all, and focus on getting people richer to better deal with it? I thought it was supposed to be a bad idea to just keep pumping carbon into the atmosphere at increasing rates for the next few centuries and not try and address that? I thought that was the stance of the “climate-change-deniers”?… Is their point that yes, we should do as much as we can manage to RCE, but we should also focus on approaching the problem from different angles, like poverty and R & D?… Or is the point that we shouldn’t bother worrying about RCE right now and have faith that other technologies and economic improvements will give us the only viable answer to this real and steadily growing threat? Or is the point that it’s not even that: in the next few centuries, it won’t get out of hand and it will only cost a very small amount of resources to “deal with”?

TL;DR — How much importance should we give to reducing carbon emissions?

Maybe some of you can help clarify that! Either way, time to do some more research into this.


Nick Ronalds
Jun 10 2019 at 4:15pm

Lomborg and his organization, the Copenhagen Consensus, make so much sense, and have already done so much good, that needless to say–he and it have been widely vilified.

Shocker: Desirable outcomes and goals have costs as well as benefits! Resources are limited and it makes a lot of sense to do those things first that yield the greatest benefit! Every charitable organization should take such principles into account (and doubtless some do to some extent).

In a just world, Lomborg and/or the Copenhagen Consensus would get a Nobel Prize (they can justify one for Peace, given the history of that prize). That will never happen given twisted political realities, at least for foreseeable decades.

Jun 10 2019 at 8:58pm

Allow me to just say a few things from a commoner’s perspective: oil is NOT infinite, carbon emissions are about more than just the temperature, and our air is getting bad in general. Everyone can probably agree on this EASILY.

Listen, just to bring the point home: I constantly wonder about whether making money is a good/bad thing for the planet. Is an electric car really better? By how much? What would motivate me to invest in solar panels versus campaigning for better nuclear power? I think both have interesting benefits if not entirely related. But let me get to the point that hit home to me today. Mankind is dependent on technology at this point to live. We have no choice but to deal with the planet we have and make it work. I am often much more concerned about aquifer depletion and various other things than about global warming specifically. To what degree they are related, I’m not making a call on that right now. But one thing is for sure, unless we are all willing to just go back to living in a stone age and living in wood huts and living off the land, we have no choice but to go forward and we all have the rest of our lives to live.

This is not even to mention that even if I think that I would like to have an electric car, (even though I think it would make me happier to have no car at all), being poor isn’t going to change the car I have. Nor is it going to change the fact that I need to have a place to live, which I would like to be designed responsibly, and on and on it goes. If everyone moved out to the land and lived on wild animals and wild plants, that for SURE would alone kill a lot of people, no questions asked.

So to all the hand-wringers out there: get wealthy and make GOOD choices for yourself and everyone around you. Then hopefully pay some taxes and promote R&D. It’s the best shot for the future. And coming from a neighsayer about economic growth, this is really saying something.

Jonah 1:3
Jun 10 2019 at 9:27pm

The most valuable information in this interview was the extended discussion, between approximately 36:00 through 55:00,of the advantages of lower-cost nutritional and medical improvements as an alternative to higher-cost policies intended to slow global warming.  What both Mr. Lomborg and Prof. Roberts seemed to miss is that almost every one of the things Mr. Lomborg suggests, such as increasing the number of persons vaccinated against disease, increasing protein consumption, and increasing the availability of contraception are things that will happen on their own at increasing rates as long as governments give people the freedom to innovate and trade.

On the other hand, all are things that will happen at decreasing rates, even negative rates, if governments pursue policies that have the direct or indirect effect of suppressing the abilities of people to create and trade wealth (what economists might call “economic growth”).  It was extremely frustrating that Prof. Roberts, and perhaps even Bjorn Lomborg, didn’t seem to appreciate that these things don’t require government programs–just like fracking, another free-market phenomenon that has decreased carbon dioxide emissions as well as facilitating the creation of, and trade in, wealth.  History shows that if governments allow people freedom to compete and cooperate to find new, mutually advantageous transactions by consent, they become wealthier, they prefer to “consume” contraception, water purification, vaccination and more nutritious food.  In other words, nothing fixes poverty like freedom.

It was also frustrating that Prof. Roberts kept arguing against things like increasing vaccinations and increasing protein consumption because he speculates that they would have unexpected costs as well as benefits, while completely overlooking the fact that climate policies that retard economic growth mean, in tangible terms, food that won’t be grown, homes that won’t be built, clothing that won’t be produced, new drugs and medical devices that will not be invented or brought to market, ad many more opportunity costs.  Those who suffer the most from policies that Prof. Roberts seems to be advocating are always the poor–those at the margin of getting enough to eat, having a roof over their heads, clothing on their backs, and medical care.

Similarly, Prof. Roberts’ implicit endorsement of geoengineering, at least in terms of manipulating the circulation of salt in the oceans (approx 11:00) without any reservation in terms of unintended consequences was curious (yes, that’s a nice word for it) in view of his protracted speculation about unintended costs of increasing protein consumption and vaccinations.

I’ve now been listening to EconTalk for a decade, perhaps a little longer.  I’ve heard Prof. Roberts describe himself as a “Hayekian” more times than I can count.  Nevertheless, in  so many of his interviews, like this one, he consistently seems to argue in favor of centralized planning and against freedom.  I can hear similar points of view on any cable news network and read them in any of the big newspapers or mainstream news outlets.  It is frustrating to hear them espoused by the host of a podcast that is funded by Liberty Fund.

Jun 11 2019 at 8:10am

Fantastic episode. And Mr. Lomborg is always a good listen.

But I can’t help but feel that while he’s working and researching in good faith, many of the ‘opponents’ are not. It seems that some are merely pushing for ends that they want for what are effectively religious reasons, and have found a problem that seems to have only one solution, the one they want.

Andrew Reimers
Jun 11 2019 at 11:13am

I work in energy economics and want to start by saying that I am sympathetic to Lomborg’s big picture arguments about climate change, geoengineering, etc. That said, his arguments regarding wind and solar are dated and in serious need of revision.

The main positive consequence of wind and solar subsidies that Lomborg’s argument misses is that they have incentivized demand, which in turn has incentivized suppliers to compete on price and develop economies of scale. As a result, prices for wind turbines and solar panels have plummeted in recent years. He is also mistaken about improvements in the “efficiency” (loosely defined) of these technologies as they have been deployed more widely. Just a few examples: wind turbines are being made bigger and higher into the atmosphere, so they produce energy more consistently throughout the day, the arrangement of turbines at a wind farm has been optimized to improve output, and weather forecasting for wind and solar plants has improved. These are all practical improvements being made in the field by firms deploying these technologies, not in a basic research setting. See attached for more information on the cost and performance improvements of wind and solar.

Bjorn also argues that we don’t spend enough on R&D for new technologies. I don’t know exactly how the numbers compare, but I’ve worked at research universities in the US and the Netherlands and in a DOE lab, and there are a ton of people working on everything from advanced materials for next-gen solar panels to algorithms and power electronics for controlling these systems more effectively. As far as I can tell, federal agencies and philanthropic organizations are throwing as much money as they can at these issues and hoping some of it sticks.

You could still make the case that the wind and solar subsidies we’ve had in the US have been cost ineffective, that a carbon tax would be more economically efficient than subsidizing specific technologies, etc. My point is that Lomborg’s case against wind and solar is not a very strong one and should be reconsidered with more up to date information.

Jun 11 2019 at 12:54pm

Excellent points. Solar farms will beat coal on cost without subsidies in the near future (3-15 years).   Wind…not so bullish there.

My only quibble…everyone in the world whose industry gets subsidies waxes eloquent about why they are really great and essential for them.  I can do the same about my field but in general they are net negatives on society and create wealth for insiders.


Andrew Reimers
Jun 11 2019 at 1:44pm

New wind is already generally cheaper than new coal on a levelized cost basis:

I am not in the wind or solar industry and would be happy to go into some of the reasons why the subsidies can be problematic. For example, the production tax credit for wind distorts wholesale electricity prices and even results in negative prices for electricity because wind generators can still make money with negative prices as long as they are getting a tax credit. My only point is that Lomborg’s argument about subsidizing/funding R&D instead of subsidizing deployment of wind and solar today ignores the benefits those subsidies have had, i.e., a substantial reduction in cost that has made these technologies competitive with conventional power plants.

Bjorn Lomborg
Jun 11 2019 at 3:50pm

Dear Andrew.

Thanks for your kind general comments and your points on wind/solar.

You’re definitely right that buying more solar/wind has made it cheaper. But we knew we could get that effect from mass production. So, my point is that if we (for argument’s sake) could reduce costs by 4x, we should have started subsidizing their increased production when they were 3.9x more expensive.

But instead we’ve done this way sooner, so we’ve spent a lot of money (about $4 trillion according to International Energy Agency) and they are still not competitive. (Some of the commenters on your comment say they’re competitive now or soon, but the IEA estimate that including the cost of intermittency, new renewables won’t be cheaper than existing fossil fuel before 2040 (

Essentially, we’ve spent, say, $1tr on solar, 95% going to existing, inefficient panels, and the last 5% on R&D for better solar. It would have been much better, if we had spent directly on R&D. We could have spent much less, and pushed forward the time when solar could possibly be competitive (of course, we should invest in a lot of different green tech, because no single tech might work out).

And yes, we’re not spending more, but rather less in % of GDP on R&D. (You can see the absolute amount, but not % here:

All the best

Todd Kreider
Jun 11 2019 at 11:26pm

but the IEA estimate that including the cost of intermittency, new renewables won’t be cheaper than existing fossil fuel before 2040

I’ve been a Lomborg fan since 2002 and disagree with him here. He has been relying on the IEA for projecting 25 years out but many of their past predictions over the past 15 years have been way off. The IEA has been an alarmist organization those years, i.e. to paraphrase their view: “we have to cut CO2 emissions and forget about renewables.” I’d encourage Lomborg to drop them as some authoritative source on renewables – they aren’t.

John P
Jun 12 2019 at 4:45pm

Bjorn, I think you have a misunderstanding of how R&D in energy works. It is not as if a lab is out there with a budget for beakers and burners. If this were true we would see grids dominated by single technologies. Like you say mass production has helped incredibly. But true innovation has taken place in learning from doing and learning from competing. Finding new ways to position panels, arrange solar cells, new materials, better logistics, and new manufacturing methods are all found out by commercialization that are unlikely to be found in an R&D lab focused on creating the best solar cell. In fact most of the costs reductions will be found on anything but the lab setting. Using a market to determine where specialized applications of renewables make sense compared to traditional alternatives will also not be determined in an R&D setting. You are correct, they are not a one size fits all application. But I’d almost guarantee an R&D budget would not get it right, profit motivation will find it. Promoting that all funding should go to R&D is a top down, centralized planning technique and I’ll take the odds on that technique failing.

Also, as someone in energy “traditional” energy, I agree with others. To declare the EIA as a reliable source on any data on renewables, especially in their forecasts, is usually a good way to find the least informed person in the room. All forecasts are wrong, not all forecasts are jokes.

Jun 14 2019 at 7:49am

Dear Bjorn,

I’m afraid the takeaway that solar and wind are “still not competitive” is incorrect, as it relies on a misunderstanding of how electricity markets work. “Cost of intermittency” is not a well-defined term, so this will be a bit loose, but we might think of it this way.

The first wind turbine installed on a system has zero cost of intermittency–almost all of the variability and unpredictably in the system comes from the demand side. But when the renewable percentage grows, the cost of intermittency grows with it. So, if wind costs c_1 (in levelized cost of electricity terms), and the benchmark thermal resource costs c_2 > c_1, we should expect wind to be installed until the cost of intermittency grows to c_2 – c_1.

So the real question is, what % of electricity can wind and solar economically provide? That will depend on the geography, cost difference, environmental regulations, demand characteristics, etc. But there are a lot of systems in which that number is in the 20-40% range already. I would describe that as being competitive.

David Nickum
Jun 11 2019 at 12:29pm

Your guest said droughts are in fact declining. Really? When we have news items like these – forecasts that summer temperatures in the Middle East and north Africa will rise over twice as fast as the global average.

Extreme temperatures of 46°C (115°F) or more will be about five times more likely by 2050 than they were at the beginning of the century. When eastern Syria was ravaged by drought from 2007 to 2010, 1.5m people fled to cities, where many struggled.

In Iran, a cycle of extreme droughts since the 1990s caused thousands of frustrated farmers to abandon the countryside. Exactly how much these events fuelled the war that broke out in Syria in 2011 and recent unrest in Iran is a topic of considerable debate.

Sure climate change is manageable and just a minor thing.

Bjorn Lomborg
Jun 11 2019 at 3:38pm

Dear David,

You might want to take a look at some of the data: the US has the *lowest* land area in drought now 2000 (


And for the world, check, fig 5 — declining for past 30 years.

The fact that you’re hearing more and more, is basically because of the CNN effect — you hear more drought, because there are more reports, and round-the-clock. Not because there are more.


Hope that’s helpful!

Jun 11 2019 at 1:05pm

Very interesting discussion.

First, millennials are scared because they have been indoctrinated to be scared.  I have never seen a generation more preached at that they are about climate.  My daughter in 5th grade came and talked about how the world would be better off without humans because we are “ruining the planet”.  Thus began our weekly tradition of tire burning to bring some balance to her life from what she gets in public school.  Their paranoia was manufactured by a state and talking to my daughter that day was the strongest argument ever against public education.  If only I could afford private alternatives….

The real problem with global warming solutions (besides the fact it stopped warming thus IPCC models being falsified by falling outside the 95% CI) is the discount rate.  Its the same problem for socialism/govt spending in general.  If I tax a dollars worth of value and destroy it with whatever great social program or environmental protection scheme, what is the long term value I could have gotten for that money.  Since it appears that growth is exponential almost all attempts to stop current or future problems hurt the future generations much more than any potential benefit to us. Only actual current existential threats (war) seem to justify much spending.

In 100 years humans may have weather control.  It might be trivial for them to adjust the world temperature. They might all live in giant cities where robots do all the work.  Or the invention of AI has occurred and we are all wiped out.  We will likely have the wealth and technology to handle problems we could not even dream of now.

Jun 11 2019 at 5:02pm

Russ, I understand your desire for humility and skepticism of what “studies show”, but in this conversation I think your pushbacks are overdone. We need to make decisions based on imperfect data. This is not a case of something must be done/this is something/let’s do this. It’s something will be done/we can make decisions on what to do based on the best use of available data or we can continue with the status quo/let’s make decisions based on the best use of available data. Pushing back is fine, but if you’re pushing back it should be with a better approach, not with nihilism. I think BL is doing great work and makes a lot of sense.

Brian Schwartz
Jun 11 2019 at 11:21pm

I’ve been somewhat familiar with Bjorn Lomborg’s work for several years, and enjoyed reading Cool It.  While I don’t agree with all of his positions, I admire his big picture perspective of opportunity costs and emphasis effective action vs.  signaling (doing what feels good).

However, and I offer the following as constructive feedback, and not a snarky remark: While listening to the podcast, Bjorn would speak for quite a long time without Russ interjecting. I no longer felt that I was listening to a conversation. Rather, I felt like I was listening to an infomercial or fund-raising speech for Lomborg’s Copenhagen Consensus Center.

I realize that Lomborg is passionate about his cause and work, as he should be, and this comes across clearly. But there was something disconcerting to me at times. Hope this was helpful feedback for both Russ and Bjorn.

David Zetland
Jun 12 2019 at 7:19am

I was worried about how this conversation might go, from the beginning when Lomborg started quoting *selected* economists to the points in which he offered all sorts of *selected* data on hurricanes, but I was glad that Russ pushed back quite a bit (even if his examples were, as some commenters have mentioned, also biased). Overall, it’s good to think of opportunity costs, and I agree with Lomborg’s main point there, but his “geoengineering or nothing, as we need to get rich” policy recommendation misses LOTS of major costs that we will experience on the road to wealth. It’s my opinion (reading Weitzman) that these costs might make that road quite hazardous.

Jun 12 2019 at 8:19am

Frustrating episode.

–What’s the justification for describing the potential catastrophic risk of global warming as a “very far tail probability”?

–Arguing that we should stop focusing on reducing CO2 emissions and instead focus on geo-engineering is like saying that a flooded basement should be addressed by pumping out the water rather than stopping the water from coming in. It’s not an either/or.

–Assuming that efforts to reduce global warming have been a waste of time (which I do not agree with) and therefore always will be so. This seems to be arguing that we shouldn’t tackle problems that are hard and that we haven’t been able to solve yet.

–Seeming to suggest that it’s only logical to worry about global warming if we’re also worried about terrorism and asteroids.

–Seeming to suggest that we shouldn’t worry about global warming because life has generally gotten better for people, including our ability to mitigate catastrophes. So should we not worry about increasing rates of divorce and decreased sense of community in recent years because life has generally gotten better?

My two cents.

Jun 12 2019 at 10:10am

I’m a big fan of Lomberg, his books, the Copenhagen Consensus agenda, and especially, his menu approach to examining the relative “payoffs” of alternatives for the next dollar (or choose your preferred currency unit) spent.

That said, I would have appreciated a closer examination of some of his claims and the methodology that yielded them.  A simple example: on climate change, Lomberg cited scientific conscensus about the probable magnitude of effects by, for instance, 2070, that appear distinctly modest and manageable.  But he fails to address outliers within the scientific community who project far worse likely outcomes, for instance the recently released paper by the Breakthrough National Centre for Climate Restoration in Melbourne (a thinktank focused on climate change).  See .

How are we to assess research and analysis such as this?  Is it’s methodology flawed — or is it applying a potentially better methodological mouse trap?  That’s the puzzling thing about the range of existing forecasts, and it seems the challenge of tackling what’s being claimed and why, and not simply cherry-picking this result or that one based on an appeal to authority.  But it does seem as if any one choosing to emphasize more modest conclusions has a burden to address studies that advance much less modest conclusions.  Lomborg didn’t do that here (perhaps he has elsewhere).

In any event, those who are alarmists about climate change at least have sources that appear grounded in science and modeling that they have, probably, highlighted with great selectivity.  But it does leave the rest of us wondering what’s signal and what’s noise.

Jun 12 2019 at 11:08am

Modeling is rarely science unless it results in a predictive model that is verified across either prior data or accurately predicts the future.  You can create a model and then adjust any of the inputs to get extreme outputs.  That’s not science that’s science-like, that’s playing with the model.  Currently no one has a working model of carbon and climate that has predicted 10 years in advance.  The authors of that paper do not present new data – they make new assumptions to get new inputs.    If they are correct than, as our guest says, nothing we do matters.  Unless we are willing to start bombing coal plants in India and China the battle is already lost.  Better to move to high land and learn to grow hot weather crops.

Jun 12 2019 at 11:24am

I agree — but modeling is presumably also applied in “science-like” ways with defensible structure and parameterization, and where possible, out-of-sample testing.  My concern still applies.  How do we mere mortals distinguish the “science-like” applications from those that might have been deliberately rigged (in essence)?  It’s still necessary to examine specific applications and defend that distinction.

Jun 12 2019 at 1:52pm

I don’t buy everything said here, but I did find this a very interesting talk, presenting a reasonably self-consistent viewpoint that I haven’t heard elsewhere.

I do quibble with the raising of “unintended consequences” to discourage suggested initiatives. I agree that unintended consequences are and have been a real practical problem, but I don’t believe that the right response is to abandon any plan which may lead to them. I think the right response is to accompany every action with a study of its consequences, and to scale up gradually from a pilot study to full scale implementation, with time between each stage to assess the results of the preceding study.

Jun 12 2019 at 3:32pm

I love listening to this podcast as Russ Roberts generally has a different take to me, on many of the issues and topics debated here and so it really helps me develop my arguments and learn more.

Bjorn makes some really interesting points which I haven’t heard before regarding climate change and our methods of dealing with it. However I could really do with some clarification, is he saying that climate change is not a big deal and so we should not bother really focussing on it? Or that because there are other much more cost-effective interventions than what we are currently doing we should focus on them? Or both?

Also when Bjorn states that the UN climate change panel found that there would only be an impact of a few percentage points on GDP. Does anyone know where I could look into that as it seems very contrary to what the media and climate change protestors have hyped it up to be.

Earl Rodd
Jun 12 2019 at 5:05pm

Well, how do I describe Lomborg , who is always interesting to listen to? To me, he is a very usual combination of someone who is helpful because he works to honestly and thoroughly use available data, yet is he a real believer in central planning. A rare combination.

But what I want to comment on is the idea of the “fat tails” or extreme possibilities. What I don’t hear mentioned is that there are fat tails on both end. I cite two specific instances:

With mitigation schemes, whether a carbon tax, or geoengineering, there are surely some near catastrophic possibilities on the negative end of things.
Even in thinking about what might happen to climate, there is a lot of talk about the “fat tail” possibilities if we do nothing. But there are also “fat tail” possibilities that actions we take will adversely affect climate in ways small and great.  For example, what if we are actually in a natural cooling trend, which historically is a bad thing due to the impact on agriculture, and man-made CO2 is keeping us warmer? Or even unforeseen serious negative effects of decreasing CO2 even as the entire earth system is adapted to higher CO2? With very low probability events, we can’t realistically compare probabilities, but we need to know there fat tails on both ends.

Jun 13 2019 at 9:23am

I have commented on this podcast too much …. but this is such a great point I don’t think I have ever heard mentioned.

What if that negative fat tail is a world government that makes China and the Soviet union death toll look amateur as they work to control the population and fight climate change?  Or whatever form it takes.  Thanks for your comment.

Jun 13 2019 at 5:58am

I discovered Econtalk only in the beginning of this year. Ever since I have listened to large number of old podcasts and get excited whenever there is a new one. Econtalk experience was akin to a religious epiphany. Of all the episodes that I have heard this one touched me at a personal level. It shattered my world view and made me physically sick. I read quite a bit about biases but when my own bias is exposed it is very difficult to accept.
I spent the last ten years trying to find a better way to harness solar energy in many universities, research centers and industry. These communities were inundated with news stories that how energy generated from solar and wind has reached grid parity beating all odds. How solar energy is cheaper than coal in some places like India that most of the new capacity added is in renewables. How articles after articles in journals like Nature predict dire scenarios if we do not rein back carbon emissions. My point is that I have not heard about how inconsequential it is to reduce carbon emissions; this argument is probably drowned out in mass hysteria. There could be many reasons for this: publication bias against non-alarmist articles; solving a bigger problem is more fashionable; or everyone is cherry-picking the data that suits their own preconceived notions. I do not believe that there is a conspiracy against the entrenched energy companies which would be strange because oil companies typically have lot of money. I have now two sets of conclusions but no resources to see what is the truth.
Bjorn Lomborg is always saying that we have to spend money on this that etc. But who are we in a truly emergent phenomenon such as markets and economy. Unless it is centralized planning which policy prescriptions in some sense are. Also it is very appealing to the electorate to say green energy would save our world than saying that we have to save people on the other side of the world. Rallying ‘We’ for something is a difficult political process and it might be at odds with individual freedom in the form of regulation.
I read comments to learn the points I missed or new angles. This time it made me realize how hard it is to shake our own beliefs off. Also I enjoy when Russ pushes back. Sometimes he might not have solid evidence or reasoned analysis with him. But pushing back, as far as I see it, is to bring out the guests’ answers for alternative perceptions out there.

Blake McDonald
Jun 13 2019 at 6:11pm

but we know that white clouds reflect more sunlight, and hence cool the planet slightly.

Don’t white clouds make it warmer because they trap radiant heat between the clouds and the ground (greenhouse effect)? Clouds are insulating the earth from the cold atmosphere so it retains heat. When it’s a clear sky heat from the sun is able to escape into the atmosphere so it tends to be cooler. Clouds that reflect heat back into the atmosphere also reflect any heat that makes it though back into the ground.

Ben Riechers
Jun 14 2019 at 11:31pm

Several times in the past year or so you have chastised, gently but regularly, the conventional approach economists take when they exclude important, but hard to measure aspects of our overall well-being. Late in this interview, you mentioned it again. It isn’t clear to me what you think should be done about the current approach. I doubt you want to see economists mingle hard numbers (such as they are in economics) with some sort of an assessment of other more subjective factors that impact well-being.

Perhaps your chastisement should be for the users of the information or how economists represent their work. It seems to me that political decisions are made only on the numbers or only on the subjective factors whereas corporate allocators of investment resources are very well practiced at considering a range of factors that they use to adjust what might be a numbers-only decision. The best poker players know the numbers. They can’t get to the finals without knowing the numbers, but they rarely win just knowing the numbers.

We don’t need the numbers people to change what they are doing. If anything, we need the numbers people to have some humility as they speak to decision makers…perhaps suggesting that the numbers are almost always important and almost never represent everything that should go into a decision.

I never miss an episode and I’ll be listening for a clarification of what you think should be done.

Michael Pettengill
Jun 15 2019 at 8:36am

Economies are zero sum.

Your high cost is my high income, and my high cost is your high income.

Listening to Lomberg, US coal miners became much better off during the 80s when Reagan focused on cutting costs, especially energy costs. He killed off US solar and wind energy development while coal production/consumption doubled and cost cutting slashed labor costs in half. The 50,000 now unemployed coal miners in Appalachia were clearly much better off, by Lomborg’s metric of lower costs providing greater benefits.

(Europe gained the lead in wind and solar in the 80s, until Germany outsourced solar to Asia as is ceased to have excess labor.)

The US has cut costs in manufacturing by both automation and outsourcing to Asia where they invest more heavily in cutting manufacturing costs by better processes and automation. Again, Lomborg argues the US heartland must be much better of by the large cost cuts in manufacturing in the Midwest.

And US farming has slashed costs by paying a big share of costs to patent holders on licencing for GMO, which again makes the farmers much better off, so increasing farmers are aging out and selling farm to Chinese corporations to run the farms.

After all, those advocating for lower costs are not targeting rents (royalties, licensing) and profits, but labor costs, the wages paid and the number of workers.

Do not confuse the cost cutting of bringing  a completely new technology to market which then displaces other consumption (human consumption is limited), allowing a brief period of extremely high growth in production/consumption (zero sum, no production increease without consumption increase). A hundred years of growth is a very long time in the context of 5000 years of documented cost cutting in farming, tool making, manufacturing, transport, …

Elon Musk led the effort to cut costs in high performance electric vehicles which required “inventing” the gigafactory. Tesla is planning at least ten over the next decade, and now the Germany automakers are planning to build gigafactories. But there will be a maximum number of gigafactories building batteries and vehicles, and using old vehicle batteries as sources of raw materials. European is still expanding its wind turbine factories as it learns to build even bigger turbines, and build them for the seas (and hopefully thanking President Reagan for US cost cutting in wind engineering), but that growth will cease.

If I’m 50+ years younger, I want an economy greatly increasing costs so I have plenty of opportunities to earn a high income. At 70+, letting capital, nature, economies decay to cut costs to me benefits old people poorer than me financially, but I get excited by watching high costs produce high performance electric sedans, Falcon Heavy rocket launches, and the new Tesla Truck and Semi and then the Roadster that will beat the Lotus whatever.

Fighting climate change means excitement! And jobs for kids with dreams I had 50+ years ago, when I was becoming a high cost worker. Building personal computers that cost about $50,000 – today what I worked on then is about $5. And the growth is gone, with jobs building computers falling in number. But I see eliminating fossil fuels and getting electric vehicles to everyone as a fifty year career.

Marvin Lutz
Jun 15 2019 at 10:09am

I love Econtalk.  Many thanks to Russ for doing a great job for years.  I do wish this episode had stayed focused a bit more narrowly on climate.

On that front, I find Lomborg’s contention that humankind, through increased economic development along with improving technology, will be able to adapt to a changing climate as somewhat persuasive.  However, and Russ pushed back a bit on this, I am much less certain that our natural environment can make the transition.  Yes, the world has changed more drastically in the scope of geologic time, but it has not done so during the era of human civilization and has infrequently (ever?) changed so rapidly without great disruption.  Also, given pressures on habitat already extant, I question how our wildlife can be preserved for future generations when the additional stress of global warming is thrown into the mix.  As Russ mentioned, it may be hard to put a price on this resource — I posit it is very steep.

Another issue I’d like to have heard explored more is the side effects of geo engineering.  As one simple example, even if we humans find a cost effective way to control temperature without other undesirable weather disruptions, the higher CO2 concentrations in the atmosphere lead to higher ocean acidity, which its attendant concerns, which are possibly catastrophic.

Auke Hunneman
Jun 16 2019 at 9:40am

Even though I am fully in favor of carefully evaluating the different policy alternatives that we, humans, have, I find the anthropocentric approach to climate change in this Econtalk episode worrisome. As recently as this week, research by White et al (in Nature) has, for example, shown that spending more time in nature is associated with better health. This is just one example of how the the ecosystems that we live in impact the human enterprise (that cannot be easily measured). The extinction of many plant and animal species will undoubtedly have negative consequences for our mental and physical well-being and our welfare (medicine, biomimicry, etc.). The episode mentions multiple times, the possibility of far tail events, but as Nassim Taleb has successfully pointed out, even though these events may be unlikely their impact might be catastrophic. Hence, we need a precautionary approach to climate change and avoid it as much as we can.

Maureen Wood
Jun 17 2019 at 4:28am

I loved this podcast because it addressed a lot of concerns that I have had about climate change policy.  I am going to look at the sources of data to understand for myself whether Dr. Lomberg’s claims are true, but he certainly addresses some important concerns I have about our current direction. 1) That our energy demands are increasing annually as we discover more and more uses for such energy-eating technologies as fast computers for data processing (the foundation of big data and machine learning), 3-D printers, and robotics. In contrast, consumers are encouraged (or guilted by their friends) to reduce air and car travel, efforts which amount to a drop in the ocean compared to these growing demands, and are simply incompatible with the needs of daily life (to get to work, to do business).  In addition, exploitation of various carbon fuels is increasing, not decreasing, although many of the newer sources, e.g., natural gas, have less climate change impacts.  This seems to be a partial solution that is ignored.  With energy demand as such, I cannot see how the world is going to ween itself away from non-renewables, but we can move towards renewables that have less climate change impact.  This message seems to get lost somehow.

2) That many technologies to offset energy demand actually also have negative consequences or somewhere in the chain have negative consequences.  For example, hydrogen-based and electric vehicles are a good solution for pollution in urban areas, but they are not a solution for climate change. In fact the components of high-powered batteries for vehicles and the ubiquitous cell phones require rare earth metals and therefore, a considerable expansion in the world’s mining activities, that has its own set of environmental challenges. Likewise, some national policies to promote biofuels are causing farmers to grow crops just for this purpose, using considerable energy and pesticides to do so.

3) The focus on climate change is taking away substantial resources from environmental problems we have right now.  As someone who works in a traditional environmental fields, the effect has been dramatic.  Resources are being torn away from research and implementation of problems that we have right now from any environmental issue that is not seen as connected to climate change, including air pollution  control and chemical accident prevention, both of which increase with mining and energy usage and exploitation, and  that we know how, but need resources, to control.  Indeed, I think Dr. Lomborg is correct that we should be focusing a lot more on controlling impacts and investing in technological solutions to the potential problems of climate change than on trying to stop it by recommending abstinence, which seems to be the main thrust of our current policy recommendations that are, in fact, going almost nowhere.  Our past environmental policy successes, of which there are many (even if we can do ever more), have been finding practical solutions that do not seek to refrain from the polluting activity but to stop or control the harmful part of activity.  In my experience, we are not capable of stopping economic activity that brings us substantial  benefits because it goes against human nature.  I agree that we have achieved very little with the increased resources in climate change, and I think we are pursuing a losing strategy right now.

Todd Kreider
Jun 18 2019 at 10:40am

1) That our energy demands are increasing annually as we discover more and more uses for such energy-eating technologies as fast computers for data processing (the foundation of big data and machine learning), 3-D printers, and robotics.

Actually, in the U.S., per capita energy consumption peaked in the 1970s and is about 20 percent lower today with most of the decrease occurring after 2000.

Jun 18 2019 at 3:01pm

“It’s not obvious” why a carbon tax that reduced other distorting taxes like corporate income taxes or the wage tax would have a significant negative impact on growth in real income, thought there would probably be a shift toward investment (in CO2 saving technologies) from consumption.

Jun 18 2019 at 3:11pm

Also worried that a geo-engineering approach only fails to deal with ocean acidification costs.  Maybe that will be the way to go while transitioning from net positive to net negative CO2 emissions, assuming that at some point the costs of removing CO2 from the atmosphere will exceed that cost of further gross reductions

Jun 20 2019 at 9:19am

I guess I missed the point of why we’re bringing up a book from 20 years ago.

Marilyne Tolle
Jun 20 2019 at 3:17pm

I have three points to raise, which I’ll do in separate posts for ease of reading. Grateful for people’s views.

1. Climate change or global warming?

Ten or maybe 15 years ago, people talked about “global warming” but now it’s all about “climate change”.

At first, I thought this was part of the euphemisation wave that has swept the world over the past decades.

On the face of it, global warming and climate change seem to refer to different things: global warming to the rise of the average global temperature, and hence the mean (first moment) of the distribution; and climate change to extreme global weather events (very hot and very cold), and hence the variance (second moment) of the distribution.

But on second thought, it looks like climate change and global warming are two sides of the same coin. Much like high inflation is volatile (and low inflation is stable), rising temperatures seem to go hand in hand with greater temperature fluctuations.

If that is the case, global warming can be thought of as a marker for climate change, which would explain the political focus on limiting the rise of the average global temperature to 1.5°C in the next few decades.

That’s how I interpret BL’s interchangeable use of global warming and climate change: tackle global warming to tackle climate change.

That interpretation would be consistent with BL bringing up geo-engineering (which addresses global warming by “applying sunshades to earth”; “It’s artificially manipulating the temperature of the planet so that it cools down.”) as THE solution to climate change.

Marilyne Tolle
Jun 20 2019 at 3:22pm

2. Nuclear power

I was surprised and disappointed there was no discussion of using nuclear power for electricity generation as a way to cut carbon emissions – much more effective and efficient than wind turbines and solar panels, as Germany discovered with its “Energiewende” transition policy: it’s doubled its production of renewable energy at a huge cost but failed to cut carbon emissions. By contrast, Sweden and France have cut carbon emissions dramatically by adopting nuclear power generation several decades ago, and electricity there is much cheaper than in Germany.

BL argues that relying on wind and solar to cut carbon emissions is very inefficient:

“(…) we are spending lots of money. But we are spending it where we know it will have pretty much the smallest impact (…) ‘Oh, see. All these solar panels. Oh, wow, we are really doing something.’ Whereas, of course, it has negligible impact on the total temperature range.”

At this point, it would have been interesting to hear his views on carbon capture and sequestration, though from what I understand, they’re way too expensive at the moment to be viable solutions.

But then he argues that if we could invent technology that made green energies much cheaper, the scale of adoption would be so vast that it would solve global warming:

“Imagine if we could make cheaper solar panels, cheaper wind turbines, cheaper batteries, cheaper fusion-efficient, and these many, many other technologies. Imagine if we could make a green technology so cheap everyone would just buy it. Not because it was green, but simply because it was the cheapest energy. Then, of course, we would solve global warming.”

But, in a loose sense, doesn’t that technology already exist?

Nuclear power generation is undoubtedly greener than coal and, even in its latest incarnation (the third-generation EPR reactors), it is cheaper than solar and wind power production, once the storage costs of renewable energy are taken into account.

It’s easy to get spooked by sensationalistic fictionalisations of real-life events (HBO’s mini-series on Tchernobyl) or imagined ones (The China Syndrome, 1979), but nuclear accidents have been very rare and caused very few deaths. Now of course, there is Nassim Taleb’s objection of the risk of catastrophic failure.

I’m no engineer, and neither is BL, but what is his view of nuclear power?

In a recent book called A Bright Future, Goldstein and Qvist argue that nuclear power has to play a role in cutting carbon emissions (they use the Swedish word «kärnkraft» as a euphemism because the term “nuclear” is too toxic – no pun intended).

They point out that the opposition to nuclear power is largely ideological (Jonathan Haidt would say “moral”: the cultural left see nuclear energy through the “sanctity/purity” lens and treat it as a desecration of the earth) and explain why nuclear power stations are no more (even less) dangerous than dams and why storing nuclear waste is efficient and safe.

Marilyne Tolle
Jun 20 2019 at 3:26pm

3. The role of the discount rate in cost-benefit analysis

Russ opens the discussion by mentioning “cost and benefit” and BL refers to cost and benefit analysis several times throughout the podcast.

But at no point is there a discussion of how paramount the (ideologically-driven) choice of the discount rate (the so-called Social Discount Rate) is to cost-benefit calculations.

Not to get too deep into the weeds of a technical issue, but James Broughel of the Mercatus Center has an excellent brief on the issue (Equity or Efficiency? The Battle for the Soul of Benefit-Cost Analysis), where he remarks that:

“(…) the battle over discounting often includes discussions about how impatient society is and how much less weight should be placed on the consumption and welfare of future citizens relative to present citizens. These seem to be debates about the technical inputs of BCA [Benefit Cost Analysis], but in reality they are really debates about values, which in turn are debates about what goals public policy should aim to achieve.”

He explains that there are two main approaches to calculating the present value of a benefit or cost that will occur in the future:

i) The “social opportunity cost of capital” method tries to estimate the opportunity cost of (government) borrowing to fund public projects, and so calculates the Social Discount Rate as the weighted average of the rate of return on private investment (the production rate of interest) and that rate after corporate and personal taxes are applied (the consumption rate of interest). It’s a descriptive approach, based on actual market rates.

ii) The “social rate of time preference” method sees the Social Discount Rate as representing a rate of time-preference for society, where society prefers to consume sooner rather than later. It seeks to maximise social welfare, which it defines as a function of per capita consumption. It’s a prescriptive approach, which focuses on the distribution of equity through time.


The opportunity-cost approach recommends a higher discount rate i.e. it “cares less about the future” than the social time-preference approach.

But both approaches care less about the future than they do about the present, since they recommend a positive discount rate.

I’m not sure whether BL is implicitly using the opportunity-cost approach when he says:

“’What are the cost-benefit analyses for all these different things that we could do?’ So, basically make the menu for humanity: where can you spend a dollar and do the most good?”

At first sight, it seems that he places a large weight on the poor today and little weight on the poor tomorrow (high positive discount rate).

But reading between the lines, it could be that he cares equally about the present and future poor, and feels that by spending badly now on climate policies, not only are we not solving climate change, but we’re putting ourselves on a lower growth path that will hurt future generations.

If that is the correct interpretation, then BL’s discount rate is zero i.e. he values present and future generations equally.

This would be consistent with Tyler Cowen’s prescription to maximise current growth, because the power of compounding means that this would also maximise future growth.

Jun 21 2019 at 5:35pm

Does anyone have a specific link to the Nordhaus paper that includes tail risk?

When I tried looking through his work, the social cost of carbon estimates seemed to specifically exclude tail risk costs.

Jun 27 2019 at 12:26pm

I enjoyed this episode and glad to have been able to hear from someone that holds an alternative view to mine on the relative importance of responding to the challenge of global warming. I did find lots of areas of disagreement, many of which other responders have pointed out:

“If, again, you actually want to protect yourself against runaway global warming of some sorts, the only way is to focus on geoengineering” . This is simply not true. That is one way, certainly. The other is to stop putting more carbon into the atmosphere.
Does BL really believe that geoengineering on a global scale is a better response to warming than mitigation? Leaving aside the unintended consequences of creating another major disruption to global climate patterns, who decides what technologies get tried? How do you compensate the potential losers in this, as some places will experience the effects more dramatically? How does something on this scale get managed when it took us ten + years to even get country level commitments on reducing carbon emissions, most of which are not being met?
“…the Paris Agreement, which everybody, at least in principle, have signed up to in the world–and even the United States has signed up until 2020–will cost, probably between $1 and $2 trillion dollars per year. And it will achieve absolutely nothing.” Really? Just using today’s prices for solar PV, and wind (~$1/W fully installed cost) $80 trillion dollars would get you 80 TW of installed wind and solar PV. At today’s average capacity factors for those technologies, this translates into about 175,00 TWh of electricity, or roughly 5 times our current production of electricity. I wouldn’t call that nothing. This statement also ignores the fact that the $80 trillion is not being invested simply for carbon mitigation – those assets are providing a productive good – electricity – that economies need to invest in anyway.
“That’s why the only real way we are going to fix this problem is by coming up with a technology that is so cheap that everyone, not just rich, well-meaning Americans and Europeans, but the Chinese, the Indians, the south–the Latin Americans–the southeast Asians, the Africans will buy this technology.” This statement is about ten years behind the times. The Chinese, Indians, Latin Americans and the rest of the world are buying renewable energy technologies in huge volumes. They currently account for about 75% of all solar PV installations and that share is growing. In fact, many countries are spending more on RE technology installations on a per capita basis than rich developed countries, not because, or not solely because, they want to reduce carbon  emissions but because it has become the most cost effective way to generate electricity  in many parts of the world.
our research shows the best investment is by far to invest in research and development of green energy.” The widespread deployment of wind and solar PV technology has driven the cost of these technologies down by about 90% over the last 15 years and costs continue to decline. I do not think there is an R&D program out there than can claim that type of success. Create incentives for deployment (ideally a carbon tax) and allow the market to compete to find ways to produce these technologies more cost effectively – it has worked so far, we don’t need to wait until we have a magic bullet.

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TimePodcast Episode Highlights

Intro. [Recording date: April 16, 2019.]

Russ Roberts: My guest is Bjorn Lomborg.... Our topic for today are the costs and benefits of attacking climate change.... Let's start with your assessment of the risks from global warming. How serious do you think it is?

Bjorn Lomborg: So, I think the first thing to really realize is that I'm not talking about this as me. I'm simply trying to take some of the best people who have been working on this, typically with the U.N. Climate Panel [United Nations IPCC, Intergovernmental Panel on Climate Change]. So, when you are asking what is my assessment, I'm simply answering: What is it that the U.N. Climate Panel is telling us. Because, I'm just working in economics. I'm not the science guy who has been looking at this. There's lots of economists who have been looking at this. What they find is: Global warming is a problem; it's not the end of the world. By the 2070s, the net impact of global warming will be somewhere between the equivalent of 0.2 and 2% of GDP [Gross Domestic Product]. So, it's the equivalent of probably 1 recession over the next 50 years. By the end of the century, unmitigated global warming might cost somewhere between 2 and 4% of global GDP. Remember: by then we'll probably be somewhere between 5 and 10 times richer; so, out of a 1000% increase, we'll still have to pay 2 to 4%. That's certainly a problem: certainly not the end of the world.

Russ Roberts: A lot of people, though, worry about a worst-case scenario. There's increasing concern about extinctions; among young people there's a number of movements, as I'm sure you know, in the United Kingdom trying to mobilize nonviolent protests. There recently were some in Parliament. Do those worry you at all, those issues? The possibility of a more drastic impact?

Bjorn Lomborg: Well, I mean, I think there's two things we should look at when we think about really bad outcomes. So, we think about really bad outcomes, so the very far out tail probabilities. One is to remember that any realistic policy that we are going to embark on in the next 50 years will have a trivial impact on climate change and hence also a trivial impact on the risks of these tail events. So, in reality, a lot of people seem to be saying, 'I really, really, really worry about this far out thing that could happen, like extinction of some sort. And therefore, I'm going to pursue very costly but incredibly ineffective policies.' That just simply seems contradictory to me. If you actually worry about the really far out tail events, you should be focusing on policies that could actually help you with those events. The only way to have a swift impact on climate change is through geo-engineering. Now, it's important to say I'm not advocating geoengineering; but I am advocating that we should look into it. Geoengineering is essentially putting sunshades on the planet, if you will. It's artificially manipulating the temperature of the planet so that it cools down. We know we can do that because volcanoes do it. Back in 1991 Mount Pinatubo in the Philippines emitted so much sulfur dioxide from one volcano that it reduced temperatures about 1 degree Fahrenheit for about 3 years. So, you can--and these were global temperatures. So you can definitely do this kind of thing. That is your only real way of avoiding dramatic bad outcomes. The other part of the conversation, the other thing you need to remember, is: If you really worry about bad outcomes, surely you don't just worry about bad outcomes from global warming. You worry about bad outcomes from a wide range of other issues. And I would still argue that if you worry about bad outcomes from global warming, you should worry about a lot of other bad outcomes--like terrorism, like bioterrorism; certainly the issue of an asteroid killing off large parts of the planet, which we know can happen. And many, many other things. And Bill Nordhaus, which we'll talk about later, who is a professor at Yale University and got the Nobel Prize in climate economics, the only economist to get that, he's actually written on this. And, one of his points was: we actually do have a reasonably good estimate of how much it's worth for most people to secure the planet. Because back in the early 2000s, NASA [National Aeronautics and Space Administration] was looking at: Should we protect the planet from asteroids? Should we look for near-earth objects that might hit the planet? These are basically extinction events; and these are real extinction events. We know that they've happened before. Probably have a risk of about 1 in 100 million years. So, not a high risk by any means; but certainly a terrible outcome. They could track either 90% or 99% of these earth objects. And the extra cost of tracking the 9% was not very high. Yet, Congress decided not to spend that. It was a couple billion dollars.

Russ Roberts: [?] safe enough--

Bjorn Lomborg: Well, it very clearly tells you that we actually put a price on human survival. And, when Nordhaus does the calculation, it shows that we care somewhat, but not all that much about the planet. So, in that sense, if you worry about extinction events--which I think very, very unlikely in climate,--you should certainly also worry about it in other areas where it's much more likely; and where we also don't seem to be spending the resources. The last bit I'm sure we'll talk about later is the fact that human beings are incredibly good at adapting to many of these issues, which is probably one of the reasons why you really don't need to worry all that much about the far out, the far tail probabilities.


Russ Roberts: So, I'm a little bit skeptical of that. Actually quite a bit skeptical. I don't think we want to use the unwillingness of our bizarre and imperfect, by definition, political system to decide how 'we'--whatever that means--feel about, say, extinction of the earth. Why would you want to use that as a basis for how much we should actually care about or how much we actually care about the survival of the planet? I guess--I'd go to 99. I'm with you on that, I think. I think we are on the same page there: I'd want the 99% of the objects looked at. And I guess the question is what, in the worst case scenario of global warning, is there a policy that would be effective? As you point out, doing something because, just to do something, impoverishes us without reducing the risk--would be a mistake. But are there other things we could do, maybe the geoengineering field that we ought to be funding very seriously?

Bjorn Lomborg: So, Russ, you are absolutely right: just because you don't worry in one case doesn't necessarily mean you shouldn't be worried in general. I was simply pointing out that we make these decisions a lot of places, and pointing out that we should be different only in climate and not in all the other areas seems to me to be inconsistent. And it certainly is not consistent with human behavior; and I think a large part of that is because we've actually over the last, 5-10,000 years succeeded pretty well simply because we said, 'Hmm. We'll handle stuff when it happens.' That does not seem like an intellectually very satisfying decision; but it turns out that it very often works. If, again, you actually want to protect yourself against runaway global warming of some sorts, the only way is to focus on geoengineering. And just to give you one example--and again, I think it's important to say, we should not be doing this now--partly because global warming in not nearly enough of a problem, and also because we need to investigate a lot more what could be the bad impacts of doing geoengineering--but we know that white clouds reflect more sunlight, and hence cool the planet slightly. One way of making white clouds is by having a little more sea salt over the oceans stirred up. Remember: most clouds over the oceans get produced by stirred-up sea salt, basically: wave action putting sea salt up in the lower atmosphere and those very tiny salt crystals act as nuclei for the clouds to condense around. The more nuclei there are, the whiter the cloud becomes. And so, what we could do is simply put out a lot of ships that would basically chuck up a lot of sea water, entirely natural process, and build more white clouds. Estimates show that the total cost of avoiding all global warming for the 21st century would be on the order of $10 billion dollars. So, remember: this is probably between 3 and 4 orders of magnitude cheaper. So, typically we talk about $10-$100 trillion dollars of trying to fix global warming. This could fix it for one thousandth or one ten-thousandth of that cost. So, surely we should be looking into it, if for no other reason than because a billionaire at some point in the next couple of decades could just say, 'Hey, I'm just going to do this for the world.' And conceivably actually do it. And then of course we'd like to know if there's a really bad thing that would happen through doing that. But this is what could avoid actually any catastrophic outcomes, not just cutting carbon emissions through more solar panels--which will, in any reasonable estimate have a negligible effect over the next half century.

Russ Roberts: I want to come to that in a second, but coming back to the stirring up the salt on the oceans: first, I want to say there'd be a positive externality. I'd have been photographs; I love a cloudy sky. Especially white clouds, relative to a clear blue sky. Just my taste though. Could be the other way around for somebody. But I do think, as you point out, I think it's a wonderful opportunity for a foundation or an extremely wealthy individual, both to explore that option and to generate some data perhaps on whether it would work. Maybe it's not so feasible. Maybe it would take an enormous number of ships and it would have--you know, clog the oceans in different ways. Or as you point out, it may have other effects that we haven't thought about or don't know about.


Russ Roberts: But, I want to come to other forms of reducing carbon in a second. But before we do, I want to talk about the side effects of climate change. I think a lot of people--the reason I think there's an apocalyptic feeling among some, and I sense it among a number of young people, these days especially, who are very concerned about this--they see a lot of trends or at least they perceive trends that are alarming. There is a feeling that--I'll just pick a few; you can then just decide which ones you want to respond to. But, sea level is rising; sea ice is falling. Polar bears are shrinking population-wise. Droughts are getting more frequent. Flooding is more frequent. Hurricanes are more frequent; intense hurricanes are more frequent. Do those worry you? Do you think they are true?

Bjorn Lomborg: So, you actually have to go through each one of them, because some of them are true. So, sea levels are actually rising. This is a very predictable--one of the best sort of indicators for global warming. And we're expecting by the end of the century that sea levels will be somewhere between one and three feet higher than they are today. But, remember: This is not the end of the world. It's a problem; and it's a problem that we know very, very well how to deal with. Many nations have already dealt with it--Holland being one of the obvious countries. This is something that you can deal with very, very cheaply. Also remember, over the last hundred years, sea levels rose more than a foot. And yet, if you ask most people what happened over the last hundred and fifty years, they are unlikely to mention the fact that sea levels rose as one of the century-long important issues. It's absolutely missed--because we dealt with it. Because, actually, most buildings on the coast or close to the coast certainly get rebuilt every hundred years. So, it's something that you can very easily adapt to; and something that we have very cheap technology to deal with. About polar bears: It seems very unlikely that we actually have good data that polar bears are decreasing. We've certainly seen a dramatic increase in polar bears from the 1960s, where polar bears might have had about 5-10,000 individuals in the world. Today we have somewhere between 22- and 28,000. Many, many more polar bears. And, there is no good evidence that they are actually declining. There's no evidence that it's decreasing. But, the important point here is: This is mostly because we've been much better at actually stopping shooting polar bears. But, remember: Right now, every year we still shoot somewhere between 300 and 800 polar bears. So, I mean, if you want to do something about polar bears there's a much easier policy: Stop shooting polar bears. If you look at some of these other things you mentioned: Droughts actually, the U.N. tells us there's low confidence in the scale, even, of droughts. And, for the United States, the U.S. Climate Change Science Program (CCSP; renamed USGCRP, U.S. Global Change Research Program) tells us droughts have for the most part become shorter, less frequent, and cover a smaller portion of the United States over the last century. So, we're simply wrong on droughts. Again, in the future, there's possibly going to be more droughts some places. Likewise, for floods: We're actually not even sure globally whether there are more or less floods. The U.N. Climate Panel tells us they don't even know: they have no confidence in the sign of the trend. Certainly, the cost of U.S. flooding has decreased over the last century--dramatically so. It's probably decreased from--a typical cost back around 1903 was about 2% of GDP. Today that cost is back to 0.2%. So, we've seen a dramatic decline in these costs. Likewise for hurricanes. We've actually seen fewer hurricanes hitting the United States, not more. And again, it's important because as you mention, a lot of people have the sense that there's more and more hurricanes. What they are actually seeing--and I think this is important to point this out, once again, is more the CNN [Cable News Network] effect: that we see more and more of every hurricane that happens. And so we get the impression that things are getting worse and worse. But really what we are seeing is, we are seeing more and more of it. Actually, if you look at the continental land-falling of hurricanes in the United States, both the--all the hurricanes have been declining, not increasing. And also the strong or the major ones that are Category 3 and over also have been declining, not increasing. And again, this simply bears repeating: We get the impression from media that this is happening more and more; but in reality if you do the numbers it's happening probably less and less. Certainly for hurricanes in the United States. But the reality here is we are getting a very bad picture from media, because we are only looking at how often do we hear about it. It's a little bit like back in the 1990s, if you remember, everybody talked about how there's more and more crime, while all the crime statistics were actually declining. But we saw more and more about these stories, about a person being raped or home break-ins, and all these terrible things happening. And they're really all true. But we're not going to be able to make good policy decisions unless we actually look at the data. And the data clearly told us back then we were seeing less crime, not more. And likewise, what we are seeing here is, typically, that we actually tackle climate catastrophes better and better. Not worse and worse.


Russ Roberts: Well, the Union of Concerned Scientists claims, "Recent research in this area suggests there has been an increase in intense hurricane activity over the past 40 years." They concede it's hard to measure. I'm sure they had to do some statistical analysis to figure that out and to try to isolate certain kinds of hurricanes. But, there are some--there are data points that are not as cheerful, I suspect, as the ones you are summarizing. Do you think that's true?

Bjorn Lomborg: Yes. So, you can definitely argue that there has been an increase over the last 40 years. That's partly because you are starting at a very low-impact and you are ending up in a higher impact. You are also looking at a data set that we know is terribly skewed, because at first, 40 years ago, we had very little satellite information. So, you missed most of the major hurricanes. Whereas now you get every little hurricane that's delivering. And that's why there is a very good argument that land-falling hurricanes is much harder to mis-count. And that's my preferred message. But the reality here is, much more importantly to recognize it is very unlikely that we are seeing a dramatic increase. We've seen a small decrease in landfalling hurricanes. But it's very unlikely that we are seeing a major increase in any of these impacts. And, certainly, if you look at it from the account of, 'How much does this cost society?' we have seen a decline in all the major impacts. So, in U.S. flooding; in hurricanes; and certainly if you look globally on all weather impacts, you've seen a decline in cost from about 0.3% to now about 0.25%, since 1990--so, the last 30 years.

Russ Roberts: And that's worldwide.

Bjorn Lomborg: This is worldwide.

Russ Roberts: You talk about how--it's a beautiful chart--climate-related deaths over the last century have plummeted.

Bjorn Lomborg: Yes.

Russ Roberts: And, regardless of what's going on in the climate--could be getting worse, actually--but we could have more hurricanes, we could have more droughts, more floods, and we could still have a lot fewer deaths, because we've adapted. We're richer. We have more air conditioning to deal with hot weather. We have stronger buildings because we can afford to make them stronger to deal with flooding, or hurricanes, earthquakes, and so on.

Bjorn Lomborg: Yes. And, whenever I show this graph, people are just astounded. It's from the International Disaster Database. Which is the best database that we have. It certainly is under-representing the impacts in the early years of the last century, simply because there is less data-gathering. And yet, what it tells us is, in the 1920s, on average, every year, half a million died from climate-related deaths--like floods, drought, storms, wildfire, and extreme temperatures. Today, despite the fact that the world has quadrupled in population since then, the number is down to about 20,000 people a year. So, a 95% reduction every year. And as you quite rightly mentioned, this has very little to do with climate and everything to do about higher living standards. The fact that we pulled so many people out of poverty--because one of the worst things that can happen to you if you are in a catastrophe is that you are poor. Because then you can't adapt. You will live in a shanty town; you'll have cork[?] roof over your head. And then when a hurricane hits, it's going to hit you dramatically. That's why when a hurricane hits Florida, yes, it costs a couple of billion dollars and it kills a few people. But the same hurricane hitting, say, Guatemala, will cost a third of their GDP and will kill, you know, tens of thousands of people and actually demolish their economy for years to come. So, the real point here is to recognize that in any realistic world, we have become much, much more resilient to weather. And of course that tells us something. It tells us: If you want to help future people, dealing with climate change, how do you best do that? Do you do that by cutting carbon emissions and hence getting them a worse climate but a slightly less worse climate in 100 years? Or do you mean--

Russ Roberts: You mean a worse economy. You meant a worse economy, I think. You said a worse climate.

Bjorn Lomborg: No; no, no. I actually--Sorry. If you cut--you also deliver a worse economy. But if you cut carbon emissions, you will still see carbon emissions go up. You will still see temperature go up. But not--by slightly less. So, you will have a worse impact on climate, but slightly less worse by the end of the century. So, there will still have to be many of these problems. Or, do you actually want to pull them out of poverty? Which will mean that they will be much better able to tackle anything climate throws at them. Plus, of course, it will be better for them in all other respects. They'll be less poor; their kids will die less; they'll have better nutrition; they'll have better schooling. All these other things that matter immensely. I'm always surprised by the way that people who are focused very much on climate really only think the knob that we can turn is the climate knob: We can cut carbon emissions or not cut carbon emissions. But the reality of course is: We can do a lot of different stuff. And we have to ask ourselves, 'Where can we, if you will, turn the knobs so that we help the world the most?' Not just 'Where do we turn the knob so that we cut carbon emissions? Because that's the only thing I care about.'


Russ Roberts: Well, I think that's a deep, and often the, the absolutely right way to think about it. Let me push back on that formulation with this policy that you are talking about. In the United States, we are of course, one of the larger, being a rich nation, with 330 million people, we put out a lot of carbon into the atmosphere. And we could change that in a variety of ways--the most obviously being attacks on carbon directly. We could also subsidize alternatives. We'll talk about that in a minute--that would perhaps reduce the rise or the rate of increase, or maybe actually decrease carbon emissions. And, we can do that. Congress can do it tomorrow. Um--but we are really not good at reducing poverty in the rest of the world. I don't think we know much about that. So, I have my ideas better to do that, better than I think other techniques; but I could be wrong. And the track record is really bad. We spend a lot of money trying to fight poverty--at least allegedly--trying to fight it with very little impact.

Bjorn Lomborg: Mmmhmm. Yeah. So, uh, you are absolutely right. We could cut carbon emissions a lot. But, of course, the reality is: We haven't. Almost no state has done so very well. The perhaps obvious exception is the United States, because you basically discovered shale gas, and that has caused gas to be much cheaper than coals. So you switched from coal to gas. Especially in the electricity production. That's cut carbon emissions more than any other nation over the last 10 years. So, but, obviously, that had nothing to do with climate policy, whatsoever. But there is obviously a lot of ways that we can make people more resilient. Remember it's not just about pulling people out of poverty. But just to address the poverty point very head on: We know one of the best ways to pull people out of poverty is by allowing them to get into the global marketplace. If we could have more free trade, we could have much richer, much less poor people around the world. We estimate that had we successfully concluded the Doha Round--I don't want, you know, it's pretty much just dead now, but that was the big thing where the world could actually deliver more free trade. We estimate, had we just had a successful Doha Round, we could have lifted 170 million people more out of poverty. We could have made every person in the developing world about a thousand dollars richer, per person, per year, by 2030. That would do an immense amount more good for the world than pretty much any other policy you could imagine. But, of course, nobody talks about that, because there's way too many concentrated interests to tell you, 'Oh, don't have free trade.' You know, 'Subsidize my particular thing.' And there's very little general interest in focusing on free trade. Because, you know, the benefits are spread so thinly. And they are mostly for people who don't have a strong voice in the global community. But apart from all those, but apart from this very obvious policy we could also be focusing on just getting better food to people around the world. That would help them get richer by themselves simply because they would be, their kids would develop better, they would be more alert in school, they would learn more and they would become more productive as adults. We could do that, by, for instance, getting GMOs[? Genetically Modified Organisms] out. But also much more uncontroversially just increase the level of investment in research and development into yield increases, which would deliver much more food per acre or hectare that you'd be covering. And there are many, many other policies that we could do like these, that are just sort of fairly cheap and incredibly effective. So, yes: I do take your point that we could do CO2 emissions. We haven't done it, really, neither in the U.S. Congress or anywhere else. And, we could actually, likewise, be doing some other policies--by the way, we haven't done anywhere, either. But that would be much cheaper, much, much more effective, and would help many more people, much better.


Russ Roberts: So, I’m sympathetic to the idea that this is not an apocalyptic crisis. It's just something to be concerned about that we will probably adapt to with relatively low cost. But there are people who argue that there is this small risk of a catastrophic event, and that we ought to respond to that. And I think it's really powerful to realize what we've just said, which is, 'You know, we haven't done anything, really.' Besides creating a lot of income for people who write about it, and research it. Which is--I'm not against that; we've learned something. But that's one of the impacts. But it's striking to me that the decentralized, bottom-up solution of shale and fracking has had the largest impact. The political process has totally failed. And it's not just totally failed--I think it's important to point out that it's totally failed in a media environment that is constantly beating the drum for what the risks are. Hollywood is constantly making movies for how creepy it is. A number of prominent American politician have urged urgent action. And yet, it's not just, 'We haven't responded as well as we could.' I think we've kind of done nothing. Which should give one pause. I think one way to think about that--a worrisome possibility--is that we as human beings are just not good at taking action that is going to have consequences--excuse me--taking action and fixing things that aren't going to happen for a while. And, as you point out, you could argue it's way too late anyway. It's kind of too late. I don't think that's true. I think there are extraordinary things that could happen, many of them unforeseeable. Like fracking, which is certainly unforeseen, 25 years ago, by most people, if not everybody. And, you know, maybe we ought to be putting some bets on some wildcard--geoengineering, subsidies to some crazy--maybe a giant prize--for alternatives to fossil fuel, energy sources. I mean, I think this is what [?] should be doing. But even those aren't being done. Even those, sort of, 'Well, let's have this in our back pocket, just in case.' So, as an observer, I'm tempted to say, 'This is all just a waste of time even talking about.' But, I do find it--there is a possibility that we just have our heads in the sand. Even though I am sympathetic to your basic point.

Bjorn Lomborg: Mmm. I think there's a number of very correct points in there. Nordhaus estimates that right now the world has implemented climate policies that are equivalent to having $2 in tax on a ton of CO2. And now, remember, most estimates would imagine that we should be up to, say, $30 or $40 per ton of CO2. So, clearly those--

Russ Roberts: And those--wait a minute. So, those taxes are things like gasoline taxes that were put in place 50 years ago for highway building. Not to fight global warming, right? Or is he talking about on top of that?

Bjorn Lomborg: Well, heh, it's murky. Because honestly we have done very little. I think it's the marginal cost. This is what he--he's the only guy, I guess, who has had the audacity to try and estimate this for the world. The OECD [Organization for Economic Cooperation and Development] did an estimate of carbon taxes around OECD and found that there are several thousands of CO2 taxes on different fuels, and different situations; different policies. There's all kinds of things. So, the reality is it's very, very hard to estimate. But, you are absolutely right: Fundamentally we have done very, very little. On the other hand, it is also important to say that we are spending a lot of money on climate policies. The EU [European Union] is proudly saying that they are spending 20% of their budget on climate policies. The world is spending, probably around $150 billion dollars in subsidies every year just on solar and wind and a few other things--

Russ Roberts: So, I was too pessimistic! We are doing something! Okay! Great!

Bjorn Lomborg: Well, yes--

Russ Roberts: That's the good news--

Bjorn Lomborg: So, in some sense, we are spending lots of money. But we are spending it where we know it will have pretty much the smallest impact. And that's what's really depressing about this conversation: That, to a very large extent, climate is much more about [?]: People who worry about global warming to get them to feel good about themselves: 'Oh, see. All these solar panels. Oh, wow, we are really doing something.' Whereas, of course, it has negligible impact on the total temperature range. As I pointed out, even if we stopped using fossil fuels, you would only really see the divergence in about half a century, in temperature outcomes, simply because it's a very, very--I don't know how to put that. The system has a huge amount of inertia in it. So, there's a lot of sort of trend in temperatures built into the system. And in any realistic outcome, we are simply not going to make a difference before the end of the century. So, that's why if you really care about things changing rapidly, the only thing you can do is geoengineering. But, more realistically, I think that the take-home point from the fracking that we were just talking about is to recognize: The idea of doing global warming by telling everybody, 'This is terrible. So, could you please all do stuff that you don't individual want to do, that's going to be really, really costly.' And, as you could see, for instance, in France, if you just do a little bit of it, it starts, you know, losing you, you are a majority. That is always going to be a loser. What you can do, and what we should be focusing on is much more getting policies that will actually develop technologies that are market-friendly, that people will want. So, a little bit like fracking. Everybody would like to have cheaper gas. Imagine if we could make cheaper solar panels, cheaper wind turbines, cheaper batteries, cheaper fusion-efficient, and these many, many other technologies. Imagine if we could make a green technology so cheap everyone would just buy it. Not because it was green, but simply because it was the cheapest energy. Then, of course, we would solve global warming. That's why the only real way we are going to fix this problem is by coming up with a technology that is so cheap that everyone, not just rich, well-meaning Americans and Europeans, but the Chinese, the Indians, the south--the Latin Americans--the southeast Asians, the Africans will buy this technology. That's why--

Russ Roberts: But isn't--

Bjorn Lomborg: our research shows the best investment is by far to invest in research and development of green energy. Because there's a huge underinvestment in this area. Just like there is many other areas. This is a market failure. You don't invest in these technologies because it's very hard to reap the long-term benefits, or at least reap the full long-term benefits, from a private patent because that patent will have run out by the time that will have a huge global impact. And so there's a huge public benefit, but not a private benefit. That's why we should spend much more money; but still much, much less than what we are spending on climate policies and investing in research and development. Both make the world a safer place for climate. And it would be much cheaper and much better, and also, hey, give us better energy technologies.


Russ Roberts: Isn't that where a lot of that $150 billion worldwide is going, though--toward subsidizing research in those green technologies?

Bjorn Lomborg: No. No. You would imagine. But no, unfortunately almost all of it goes to spending it on known inefficient solar and wind. Right now. We are putting up a lot of it. And we need to subsidize it because it's inefficient. Now, the effect of putting up lots of it is that we give money to these companies that will then invest some of this money in research and development into making better next-generation solar and wind. That's great--but, you know, say we spend--

Russ Roberts: Wrong way to do it--

Bjorn Lomborg: $150 billion[?] dollars. If you spend that, and that means those companies spend $5 billion on research and development, why the hell wouldn't we have spent the whole $150 billion on the right investment--namely the investment in research and development? And also, remember: They are only going to spending on innovation that they know they can monetize in the next 5 years. We need to spend it in a way they will monetize it for human civilization over the next 50 years. That's probably also a somewhat different tack.

Russ Roberts: What I really like about you, Bjorn, is that you care about the numbers, and, uh, a part of me recently has gotten increasingly disturbed that we as economists spend too much time on the numbers because we tend to ignore things that can't be measured. But, in areas we are talking about, numbers capture a lot of what we care about. Not necessarily in the right magnitudes. We are talking about loss of life. And we are talking about cultural loss--which are, these are hard to measure. But when you are talking about people, just, say, dying: you have different ways to save people from dying. You want to save more than fewer. That's the only part of the--if all else is held constant, that's the utilitarian piece of me. And you argue that, uh, we have lots of other things that people die from right now that are really--we could do something about. And yet we tend to focus overwhelmingly on climate change as the single most important environmental issue. It may not be.

Bjorn Lomborg: Yeah. You are exactly right. And, and, [?] I share with you the idea that cost/benefit analysis is by no means perfect. It doesn't encapsulate everything. But again, I think of it more as a menu for society. So, basically, you know, we put on the prices and sizes: what are you going to get if you order this item on the menu? How much will it cost? What are the calories? What's the salt content? And, you know, we're the kind of guys who take a look over the menu and say, 'You know what? Spinach is really cheap and it's good for you. You should eat that.' And you might not like spinach. And that's fine. But at least it's a good way to give you an indication of what works. What is important. And certainly, when you are orders of magnitude out, I think the numbers can definitely help you. Just to give you a sense, the--Nordhaus, as I mentioned earlier, the guy who got the Nobel Prize for climate economics, he's actually done a cost-benefit analysis. And climate, again, you can disagree with it. You can say maybe he hasn't included everything. He has certainly tried to include also these far tails and everything. He finds that what we should do is put a higher tax on CO2 than we have today; we should do that globally. If we manage to do this globally--efficiently--that is, coordinate a single carbon tax across all countries from China and the United States and the European Union, and Latin America and Africa and everybody else, across the entire sanctuary, we can actually cut temperatures by more than 1 degree Fahrenheit. Remember: that still means we are going to be seeing almost as much temperature rise as we would have seen had we done nothing. And what he also shows is that if we do much more than that, what probably all politicians are talking about, not only is it going to be impossible--you know, the 1.5 degrees Centigrade that everybody talks about is just not doable--but if we try to just approach that with doable policies, we are going to end up spending much, much more money than the benefits we are going to create for future generations. And I think it's important to emphasize: The guy who got the Nobel Prize in climate economics tells us we should do more than what we are doing today. But if we do a lot more, which is what all politicians are arguing for, we'll actually end up making the world worse off. That's a bad deal. And that's something we should take care of.

Russ Roberts: Well, yeah, um--

Bjorn Lomborg: Of course, as you just pointed out--sorry.

Russ Roberts: I'm going--let me respond to that. And then you can add what you were going to say. I don't think everything that's important in that calculation is monetarily measurable. I don't think we get the tails right. I doubt he gets the tails right. And I guess, just to take a trivial example, if we lost all the wildlife in the world--and let's assume that has no impact on human wellbeing directly, but we just couldn't enjoy it; and all we did was destroy the, kill all the wildlife in the world--let's say, big fauna. That would be a tragedy that I would have trouble putting a monetary value on. It's kind of like, um, kind of like Notre Dame, the cathedral which tragically burned down yesterday. Not to the ground--some of it was saved. It can probably be recreated in some fashion, maybe quite accurately, by the way. It could be a really interesting emotional question whether a replica of the spire will be okay--especially if you are a Catholic, if you are a French person. You know, is that going to be an acceptable change? And, you know, I don't know the answer to that. But I wouldn't want to just say we'd look at the monetary cost of that repair to be the effect of the fire. So, there's some things here that can't be quantified. And my claim--

Bjorn Lomborg: Oh, absolutely.

Russ Roberts: My claim is, even though I like your menu argument, and I did it myself in defense of cost-benefit, when things aren't on the menu it's really hard to remember them. And, I just--I'll just mention that.

Bjorn Lomborg: Oh; sure. And, look: I think, just on your precise argument on losing all wildlife, all other species--that just seems--partly I just can't see any mechanism by which we would actually see that happening. But also, again, if you actually want to conserve wildlife, it's surprising that most people are talking about global warming, whereas, of course, the real impacts are that we are losing a lot of land for human agriculture. One of the ways that we could avoid that is by making agriculture more efficient, so we would use less of it. That's what happened in much of the rich world; and that's what we need to happen in the poor world. It's about[?] invasive species; it's about setting aside places to protect some of the things that we really care about. Those are the effective policies; and we know those are effective, and much, much more effective. So again, even if you care about some of these things, I think you really have to look hard on whether you are getting your value, also, in terms of species, from climate policies. But, let me just--because as you also alluded to--one of the things that we try to do with Copenhagen Consensus, which is a think-tank that gets together a lot of the world's top economists who look across a wide range of areas and say, 'What are the cost-benefit analyses for all these different things that we could do?' So, basically make the menu for humanity: where can you spend a dollar and do the most good? And what we try to find is, there are some amazing things can be done; and there is a lot of pedestrian things; and there are also a lot of really stupid things--but we don't actually work all that hard on finding them, because there are still a lot of amazing things that we want to emphasize. So, just to pick out a few of those which you rightly talked about that are just about saving human lives, expanded immunization: We know that for about a billion dollars, the world could save a million kids every year. That's a thousand dollars per kid. We estimate that every dollar spent. We estimate that every dollar spent will do $60 of social benefit. That's an amazing thing. Tuberculosis: tuberculosis is sort of the forgotten disease. Everybody talks about HIV [Human Immunodeficiency Virus] or malaria. Tuberculosis is actually the world's leading infectious disease killer. And we've known how to fix it for a hundred years. So, the reason why we don't spend all that much money is because it's old, boring news. But the reality is, we could save so many people with very little cost that we estimate that every dollar spent would do $43 of social good. Likewise, there's many other things you could do with better heart attack medication. We know that that works very well in the rich world: Get that out to much of the poor world and you could do amazing amounts of good. But--and this is important--we also try to look at a lot of the things that don't specifically involve making people not lose their lives. Because, as you point out, there are many other benefits, obviously, the free trade point that I made with the successful Doha Round would be an amazing achievement: basically would have to pay off rich Western farmers, but we'd create immense social benefits for the rest of the world--we estimate every dollar spent would perhaps do $2000 of social good. But, also, we could look at universal access to contraception: about 215 million women still don't have access to contraception. If we could get that--and it would probably cost about $6 billion dollars a year, we could have these women mostly have kids when it fits in their time schedule. So they would simply plan their kids better. Typically that also means you space them better. That means your kids don't die as much. It means moms don't die as much in childbirth--so we actually estimate it would save about 150,000 women from not dying, about 600,000 kids from not dying. But it would also generate more economic growth because there would be more capital per kid; they would be more taken care of; they'd learn more in school, so on. So you'd get a demographic dividend. Every dollar spent here would probably provide about $120 of social benefits. And just one more thing: we talked about nutrition earlier on. We know from earlier experiments back in the 1960s: If you get kids good nutrition, their brains develop more so when they go to school, even if it's a crappy one, they will learn more in that school; and when they become adults they'll become more productive. They will actually be surprisingly more productive. They'll avoid a loss of income of about 66%. So, we actually estimate for every dollar spent on early childhood nutrition, you get $45 back. Also, half[?] coral reef loss--for instance, as we talked about protecting some of things that we just care about because they are beautiful--will not only mean that there will be more beautiful places for you to visit, but it will also mean that there will be more fisheries, there will be more employment, there will be more sustainable tourism; we estimate every dollar spent on protecting coral reefs will produce $24 of social good. So, there are lots of this. We actually have a whole list of this, and we have a huge book and all that stuff; you can look at it on our webpage, But the truth is: There are lots of great investments where you can spend a little bit of money and do an amazing amount of good. And that's why I'm so concerned about the fact that we almost only talk about the policies like climate, and a few other policies, that cost an enormous amount of money and does very little good. Because at the end of the day, when people look back at what we did, 50 years from now, they are not going to say, 'Oh, wow: they talked really beautifully about these problems.' They are going to say, 'Did they actually fix problems that were relevant for me?' And the answer is: We can do a lot better than what we are doing right now.


Russ Roberts: So, I'm very skeptical about all of that--

Bjorn Lomborg: Hah, hah, hah. Go ahead.

Russ Roberts: I salute your desire to improve people's lives. And I salute your attempts to try to quantify those gains. Just to take one of them: It's not obvious to me that, let's say, providing free food, just to be dramatic, to people around the world--if we could do that, which we can't. But if we could, if we subsidized American farmers and gave away enormous amounts of food to the poorest people in the world, they'd have more food. But we'd do some things to their local economies that are--given that their economies are not as dynamic, their labor markets aren't as dynamic--that might not be so good for them. And I have similar thoughts about--even things that I'm in favor of, like getting rid of tuberculosis and other forms of health improvement; you know, I'm all in favor of those; I think they are wonderful. But, in terms of measuring them, you know, if you start changing people's health and giving people access to contraception, it's not obvious how those things are going to interact. They're not going to probably have the same number of kids as they had before. Quality of life will probably be better--that their kids don't have tuberculosis, not as many would die. But it's going to change the birth--it just, it's very complicated. That's all I want to just say. So, I'm all in favor, though, of health opportunities. But I do think it's important to think about what we can do to help other people who are poor help themselves. And minimize what we do to them; and encourage what they can do for themselves. Our attempts to do things for them, our presumptions that they don't know how to do certain things are often wrong. A lot of times the choices they make that look stupid to us turn out to be quite smart. We just don't have all the information. So, I just would counsel some sort of humility there. But I also--

Bjorn Lomborg: Absolutely. Can I just--sorry, can I just, because I think it's important to have that conversation--

Russ Roberts: Sure. Go ahead.

Bjorn Lomborg: And just, on a few of these things. For instance, it would be terrible if what we did was, you know, we subsidized a lot of American farmers, we sold a lot of these, of this food, and the local market destroyed the agrarian economy to help more kids being well-nourished. But, fortunately, that's not what we're suggesting. There's a number of ways that you can do the very, very effectively, for instance by getting micronutrients into, uh, so fortified wheat and flour, or if it's rice or whatever it is that is being used in this local economy. So that's basically about subsidizing very, very small bits. Because, for each individual flour mill, it costs a little more to put this fortification in, but it will actually help immensely. When you look at giving out food, you are absolutely right. If you just try to give out food, that's typically very expensive and doesn't work all that well. One of the ways you can do that is by getting out more information, because that's much cheaper. We know that a lot of people underestimate--actually, also in the United States and elsewhere, but it's less of a problem because of fortification. But, getting the information out that it's incredibly important that your kids eat well the first two years--that's very cheap and will give them a huge opportunity in the future. As you point out, this is not about doing, you know, helping them in all their ways. It's about allowing them to help themselves better. But one of the ways that we right now see a lot of people around the world--a lot of kids around the world--they are stunted. Which is a good indicator--they are basically shorter than they should be for their age. And, the reason is that they permanently had a little bit too little and a little bit too poor food to eat. That basically means that for the rest of their life they are stuck in a lesser ability of doing what they could have done well. So, it's really about making sure that they can do the full opportunity. And we know some of these things; we should absolutely be looking at exactly how do we do that--

Russ Roberts: yeah--

Bjorn Lomborg: but we can do it in a way that helps them a lot, with very little impact--

Russ Roberts: but--

Bjorn Lomborg: So, absolutely, we shouldn't just be barging in there. But there are really smart things that we can do that would have huge impacts at fairly low cost.

Russ Roberts: I'm going to tap into my inner Nassim Taleb and point out that fortifying things, especially with GMOs, may have unintended consequences down the road. But, hard to know. But, I do think--

Bjorn Lomborg: So, I was not suggesting fortifying it with GMOs. But, we know fortification; we are doing that in many places in the developed world. Certainly, most people are doing it themselves by taking a vitamin pill. So, for instance, zinc and iron, about 2 billion people lack iron. And it simply makes them less vigorous than they otherwise would have been. And, just simply providing iron is probably one of the cheapest and most effective things we could do for the world. And, you know, one of the ways we could do that is by fortifying flour. We've done it plenty of places. There's absolutely no issue that that would be dangerous. But we do know it would avoid anemia and hence, you know, make people more productive.


Russ Roberts: It might be true, in that case. I guess the other issue, which I'm uneasy about, is the phrase 'What we know.' We don't know much about nutrition. We have a very mixed record of having elite scientists, nutritionists tell us what's good for us. Now, I think there are some basic things we do know. And I think you are 100% right that there are, tragically, children growing up in poverty everywhere in the world who don't get a chance to thrive and flourish the way they could if they had a different diet. But, I'm always a little uneasy with the top-down approach, because--

Bjorn Lomborg: Russ, let me just tell you one story--

Russ Roberts: skin in the game--

Bjorn Lomborg: Let me just tell you a story that I think is amazing and that everybody ought to know this one--

Russ Roberts: Go ahead--

Bjorn Lomborg: Back in the late 1960s, early 1970s, some researchers went to Guatemala. And found two small rural villages nearby each other, so identical in pretty much all respects. And they gave one village--they gave the kids there, good food with protein. The other one only got sugar water. Now, obviously, you couldn't have got this past the ethical board today. But the amazing thing is, that some of our researchers re-found those kids back in the early--not so--you know, when they were late 30s or early 40s. And this is about 2,500 kids. And you could totally tell the difference on the impact. So, again, this is not the kind of thing where we discuss, as calories bad for you and is fat better than, you know, sugar, or whatever. This is just simply: We know that these kids had much lower chance of being stunted, and on average these kids had better marriages, better jobs; if they were women they had fewer miscarriages, fewer kids. But crucially, if they avoided being stunted, they had about 60% higher wages. So, we know--and that's the stuff I was telling you. This is the world's longest-term study. And of course you can't do this again today. But we have very good knowledge: It's just a better idea to get more protein than getting sugar water. And I don't think this is in any way surprising--

Russ Roberts: I'm not--

Bjorn Lomborg: so we're not talking about--

Russ Roberts: I don't deny that. I don't deny that. I think that's inevitably true. Although, I'd like to see the data. I'd like to see the magnitudes. But I think the question is, if you try to implement that on a larger scale--right? No doubt, protein when you are young, better than not having protein when you are young. Calories, even when you are young better than not having any, as long as it's not too many. But, how to implement that, how to make that happen, is challenging--

Bjorn Lomborg: sure--

Russ Roberts: That's all.

Bjorn Lomborg: Yep. Yes.


Russ Roberts: Let's talk about your book, The Skeptical Environmentalist. I want to go down memory lane for me, and tell you a story about when I first found that book. The book came out, I think, in 2001. Right?

Bjorn Lomborg: 2001. Yep.

Russ Roberts: So, I get the book. Somebody told me about it. And it's--you channeled--the book is in the spirit of Julian Simon. And others who have, in a contrarian way, said, 'Actually, no; the world is getting better in a number of ways.' And you did that in a very powerful way. It was a beautifully designed, visual book. And I remember when I read it, it was electrifying for me. I called a friend of mine, and I said--I look back on this with some embarrassment, but I'm just going to tell you the history--I said, 'We're going to win.' And by 'we' I meant, and by 'win' I meant: Those of us who understand that the world is really not nearly as bleak as it appears, the data is just so overwhelming. And it was such a powerful, visual and analytical attack on the doomsday approach. And, in those days, I was an incredible optimist. And listeners know I've become less optimistic over time. I also believed that people are rational: that when they saw your evidence, they'd just go, 'Oh! I was wrong.' And I also thought that my side had all the good numbers, and the other side's numbers were all bad. So, I've lost most of those views in the last 18 years. But, your book was a tremendous achievement. And it was a, a really important call to the world to say, 'You know, it can feel depressing sometimes, but there are at least some numbers, and maybe most of 'em that are pretty cheerful.' And I, I salute you for that. And you took an enormous amount of flak for doing that. And I just would like to get your impression of what that book achieved and how it changed your life. And how you've dealt with the responses to it.

Bjorn Lomborg: Yeah. You are absolutely right. That, you know, I did this book, actually mostly for myself. Because I have, the very standard sort of Western, somewhat left-wing worry, Greenpeace kind-of approach, 'Oh, things are falling apart, and things are getting worse and worse.' And I was inspired to read the book [?] because I read an interview with Julian Simon who said, 'That's actually not true.' And 'Go and check the data.' And that was basically what this book was an outgrowth of: Checking the data and realizing that on most of the important areas, things are getting better. As you say, there was a lot of flak. And when I think back on it, I'm sometimes astounded. I know that here in Denmark we had a local editor, what you could reasonably call the New York Times of Denmark, sort a slightly left-leaning, very reputable newspaper: He published the first articles with me. And he basically said, 'If I'd gotten the same kind of flak, I would not have been able to stand up.' And I was always surprised about that, because he was a really strong guy. And yeah, he was very sure of his opinions and willing to take a lot of, you know, flak for things. And I think, what never dawned on me was that when people are sort of thrown off by people, by other people saying, denouncing you and saying, 'How dare you write these things?!' the only story that I ever hear is the story that they apparently tell it at Harvard Business School--sorry, Harvard Law School--where they say, 'If you have a strong case, pound the case. If you have a bad case, pound the table.' All I heard was people pounding the table. And it was never sort of, 'That's not an argument. Show me some numbers that indicate this is wrong.' And that's really the approach that I still have. And that I think most academics probably have to most issues. This is not a popularity contest. I don't care whether you like me or not. I care whether you have better numbers that show something else. And that's why, you know, when I talk about global warming, I think you just have to point out: Look, it is a problem. It is by no means and in no respect the end of the world. And this is about asking how much can you do. If we are going to spend a lot of extra resources, is this really the place where we can do the most good? Just to give you a sense of proportion, the Paris Agreement, which everybody, at least in principle, have signed up to in the world--and even the United States has signed up until 2020--will cost, probably between $1 and $2 trillion dollars per year. And it will achieve absolutely nothing. You won't be able to measure the impact in a hundred years. That is probably a pretty terrible way of spending about $80 trillion or so dollars over the next half century. So, I would suggest that we should think about how we spend it differently. Now, if people get all apoplectic about that and say, 'You can't say that. That's not allowed,' and 'We should be worrying much more about--,'; well, good on them. I simply want to point out there are good data; and some of the best economists tell us there are amazing places where we could spend our money instead. And that's what we should be doing. So, my reaction from the whole, you know, Skeptical Environmentalist, and I'm very, very pleased and thank you very much that you have enjoyed the book, I'm a little disappointed that you might have given up on a lot of these, uh, these uh points, though. Because if we look at the general issues that really matter for people--that is, how long do you live? And how much income do you have? And what's the state of your environment? Those are typically some of the three best indicators of what is the welfare of human beings. They are pretty much all increasing. They are all getting better. Now, we could still wish that they were getting even better, and I'm trying to point out that we waste a lot of money under bad policies. But, overall, despite all of this inefficiency, we are still getting better. And so, my goal is life is not contesting that. It's simply about trying to make it slightly better than what we are doing right now. Which is pretty damn good.


Russ Roberts: Yeah. The reason I'm a pessimist, by the way--and when I say that I've become more pessimistic--isn't because I think the trends have changed. I think, on all those trends, they are better. I think human wellbeing, material, in terms of standard of living, is extraordinarily better than it was 17 years ago, 18 years ago, and that's despite the worst recession of our lifetime. It's--enormous numbers of people have been lifted out of poverty, in China and India and elsewhere, Africa. In America. Despite the claims of others, I believe that the average person is doing a lot better. People still fight and risk their lives to come here, to be in America, because I think they realize, correctly, that their lives will be more--they will flourish more here. So I think that's all true. I think--I think we live longer, "except for the opiate crisis"--for, I think it's women. But we've lost something there. And in terms of the environment--mostly--the air is cleaner and almost, and again, in the developed world and improving in the developing world, but in the developed world there's such improvement in places like Los Angeles. Through both government regulation and private ingenuity and in terms of efficiency improvements like fracking that we were talking about or finding ways to produce, say, soda cans with less aluminum. And incredible things that creative people do. We have more forests. And the air is cleaner. Our water is cleaner. Now, it's true, the temperature is getting a little bit warmer. It may get warmer still; and that is something to be worried about. But, overall, human wellbeing is fantastically better. And yet, those are on the things that we can measure. And I'm not going to say we shouldn't measure them. I'm not going to say that they don't matter. They matter a lot. But they are not the only things that matter. And I'll just--to pick on you for a sec, when you said the three things that contribute to human wellbeing are income, life expectancy, and your physical environment: For sure, those are all really important. As are the connections we have with others. As are the feeling of mattering. The feeling of dignity. The sense of belonging. A sense of connecting to other folks. Love. All those things, I don't think we're doing so well on, lately. Now, we could argue: 'Well, we don't know how to fix those.' That's okay. Or you could argue, you could argue that some of those gains have led to some of those losses, and that we ought to be aware of those. And I think the natural tendency of economists--well, I know the natural tendency of economists. They say, 'Well, I don't,'--the way I phrase it is, 'There's no, um--dignity isn't measured in the data set, so I can't--I'm just going to have to leave that out.' But, if you leave it out and it's the most important thing, you've left out something really important. So, I think the challenge for us as policy influencers, or policy makers, or people who advise people in government, is: keep in mind that what we can measure isn't the whole story. And the human enterprise is a rich and complex one. And, our natural tendency is to not just say, 'Well, I can't measure this, so I'll have to weigh that against it,'--which I say, used to say, as an economist, and I hear you saying. Our natural tendency is to say, 'Well, if I can't measure it, I'm not even going to think about it.' I know that's wrong--intellectually, rationally I know that's wrong. But I think that's the human tendency. And I'm increasingly concerned about that.

Bjorn Lomborg: Hmm. Yeah. So, I think you both made a very eloquent argument for why things are in general getting better; and I think you are absolutely right, that we should be concerned about all the things that we are leaving out. As you also point out. And we have some good technologies and techniques to make sure that we at least leave them out less. So, for instance, we did a lot of study in India on toilets, which is a big thing in India. And we tried to look at what's the cost and the benefits of doing that. And one of the things we kept hearing was, 'You know, there's a huge amount of dignity that goes into being able to go to a toilet instead of sitting outside, and defecating with others. Especially for women: there's also some risk of rape.' And all those kinds of things. But we also have a reasonably good estimate of what people are willing to spend, and especially what they are not willing to spend. So, you can ask them and get a sense of how much is that dignity worth. But I absolutely agree with you, that when all things are said and done, you can have a pretty good first sense of what the menu is. But you have to remember that this is not the only thing. But, it's certainly also is a big thing compared to what much of the conversation in the--the policy conversation that we have pretty much everywhere in the world seems to be much more directed by who had the cutest animals or the most crying babies or the best PR [Public Relations] Agency. And surely that's not the way to do this. So, I would surmise that while we are still missing out something and we have to work really hard, and we'll probably never get all the answers, having at least part of that answer, and certainly having an order of magnitude is incredibly helpful, instead of just being driven by, you know, this one story or this one meaningful meme that seems to be driving a lot of our conversations.


Russ Roberts: Let's close with your assessment of how optimistic or pessimistic you are. You've been doing the Copenhagen Consensus Center for a little bit. Not a long time. You are very ambitious; and I salute that again. I salute your attempts to bring about better policy, even if I may worry sometimes it may have unintended consequences or be involved with some complexity across different policies when they are combined. But, you are trying to--you are not looking at the small stuff. And you should be--I honor you for that. So, the question I have is: Do you think you are going to make a difference?

Bjorn Lomborg: Hm, hm, hmm. So, thank you. And yes, we have a little bit of impact. Look. Fundamentally, a lot of things in the world are actually dealt almost outside of politics. You know: Things, and, how do you regulate your streets and your sewers and your international standards; and all kinds of other things happen sort of on the sideline. We never see it. And it's actually [?] tackled pretty well. You know, our doctors keep on running hospitals; and many, many other things work. And all of these things are helping us getting to a better place. Now, then there's policy, which is often of course about, you know, who gets what. And to a large extent it's simply about, 'If you get it, I didn't get it.' That kind of thing. And, you know, that's fair; that's what politics is about. And there's no argument on the series sum distribution [?]. But then there are some policies that we could do a lot better. I recognize that rational argument is never going to help entirely with these issues. So, you know, when we look at this--so, we've done this for a couple of nations. For instance, we did it for Bangladesh a couple of years ago, where we tried to make a menu just for Bangladesh, looking at, 'Where can you spend an extra,' their currency is taka, 'where can you spend an extra taka and do the very most good--for Bangladeshis.' There obviously there are lots of different things. We identified a lot of great ideas. And many of them just fell totally flat because they are just not right there where the policy needs them. A lot of policies that are not very effective will still get enacted. But what we did do, was we changed a few of those polishes[?] a little bit. And so, you know, we have--

Russ Roberts: That's a tremendous achievement--

Bjorn Lomborg: Yes. Exactly. It's not about getting it right. It's about getting it slightly less wrong. And I think I am actually helping with that. And, you know, for one little fish in the very big sea, I am pretty pleased with that. And I think that's the best contribution that you can do, if you are not, you know, President and have nuclear weapons kind of thing.

Russ Roberts: My guest today has been Bjorn Lomborg. Bjorn, thanks for being part of EconTalk.

Bjorn Lomborg: Thanks a lot, Russ.