Monday, November 24, 2014

Global Warming Without Fear

MALMÖ – On September 26, the United Nations Intergovernmental Panel on Climate Change will present the summary of its most recent assessment report, the fifth in 23 years. Although the IPCC is not perfect – it famously predicted that all Himalayan glaciers would be gone in 2035, when the more likely year is 2350 – its many experts generally give us the best information on the fractious issue of global warming.

Because of extensive leaks, the report’s contents are mostly known. And, because we have done this four times already, how the report will play out politically is also mostly known. But, because 20 years of efforts to address climate change have not amounted to anything serious, it might be worth exploring a different strategy this time.

The new report’s fundamental conclusion will be that global warming is real and mostly our own doing. Much will be said and written about the fact that the IPCC is now even more certain (95%, up from 90% in 2007) that humans have caused more than half of the global rise in temperature since 1950. But this merely confirms what we have known for a long time – that burning fossil fuels emits CO2, which tends to warm the planet. As climate scientist Andrew Dessler of Texas A&M University tweeted: “Summary of upcoming IPCC report: ‘Exactly what we told you in 2007, 2001, 1995, 1990 reports…’”

More specifically, the report’s June draft shows “similar” temperature rises to the earlier reports, at about 1.0-3.7oCelsius by the end of the century. For sea-level rise, the IPCC now includes modeling of glacier responses of 3-20 centimeters, leading to a higher total estimate of 40-62 cm by century’s end – much lower than the exaggerated and scary figure of 1-2 meters of sea-level rise that many environmental activists, and even some media outlets, bandy about.

Similarly, the IPCC has allowed for lower temperature rises by reducing the lower end of its estimate of so-called climate sensitivity. It is also less certain now that humans have caused hurricane and drought events since 1950. In the 2007 report, it was more than 50% certain that they have; now it is less than 21% certain.

Yet these sensible and moderate findings will be met with a predictable wall of alarmism. Many will mimic the blogger Joe Romm, who has declared that “this ultra-conservative and instantly obsolete report ignores the latest science,” and continues to claim 5º C temperature rises and six-foot (1.83 meters) sea-level rises. Romm and many others made similar arguments following the release of the 2007 IPCC report, claiming that the latest, much more alarming, research had been left out.

The bigger problem for the IPCC is that global temperature has risen little or not at all in the last 10-20 years. To be clear, this slowdown does not mean that there is no global warming – there is; but it does call into question how much.

To its credit, the IPCC admits that “models do not generally reproduce the observed reduction in the surface warming trend over the last 10–15 years.” This matters, because if the models overshoot for recent decades, the century-long forecasts are open to doubt.

Compared to the actual temperature rise since 1980, the average of 32 top climate models (the so-called CMIP5) overestimates it by 71-159% (see graph). A new Nature Climate Change study shows that the prevailing climate models produced estimates that overshot the temperature rise over the last 15 years by more than 300%.

[To view a high-resolution version of this graph, click here.]

Several studies from this year show that the slowdown could be caused by a natural cycle in the Atlantic or Pacific that caused temperatures to rise more in the 1980’s and 1990’s but that has slowed or stopped global warming now. Global warming is real, but it has probably been exaggerated in the past, just as it is being underestimated now.

This highlights the fact that the IPCC has always claimed only that more than half of the temperature rise is due to humans, although in public discussion it has usually been interpreted as all. As the IPCC emphasizes, climate change is a problem; but the report contains none of the media’s typical apocalyptic scenarios, no alarmism, and no demands from natural scientists to cut emissions by X% or to lavish subsidies on solar panels.

All of this is almost certain to be lost in the hullabaloo from lobbyists clamoring for action and media organizations hungry for bad news. Indeed, though the IPCC, according to its own principles, is a policy-neutral organization, its head, Rajendra Pachauri, will explicitly feed the frenzy by insisting that “humanity has pushed the world’s climate system to the brink,” and that we need to complete a “transition away from fossil fuels,” maybe with some kind of “price of carbon.”

As a result, the likely outcome of the report’s release will be more of the same: a welter of scary scenarios, followed by politicians promising huge carbon cuts and expensive policies that have virtually no impact on climate change.

Maybe we should try to alter this scenario. We should accept that there is global warming. But we should also accept that current policies are costly and have little upside. The European Union will pay $250 billion for its current climate policies each and every year for 87 years. For almost $20 trillion, temperatures by the end of the century will be reduced by a negligible 0.05ºC.

The current green-energy technologies still cost far too much and produce far too little to replace existing energy sources. To insist on buying these expensive non-solutions is to put the cart before the horse. What we need is investment in research and development to reduce green energy’s cost and boost its scale. When solar and other green technologies can take over cheaply, we will have addressed global warming – without the angst.

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    1. CommentedBertrand Monin

      oops sorry, one mistake in my previous calculations below.
      $5.6 trillion did not take into account the hypothesis of $20 bn policy cost since 2050. Otherwise, the result is even lower at $4.7 trillion (28% of EU's current GDP)

    2. CommentedBertrand Monin

      I think that this paragraph hypothesis are highly questionable:
      (i) in one of your comments you do take into account a 3% discount factor to evaluate the future economic benefits of todays $250bn investments; why not also discounting the annual costs of the policy for the coming 87 years? A 3% discount factor with an hypothesis of $250 bn annualy has in fact a $8 trillion dollar policy cost (fared in todays dollar value) and not $20 trillion over 87 years;
      (ii) I would assume, with great certainty, that the cost of the policy will not remain at $250 bn (in 2013 $) in the coming 87 years: government feed in tarifs and green certificate subsidies will become less and less expensive with renewable energy prices matching fossil fuel energy prices in the coming decades. It is even highly probable that no green certificates or feed in tarif subsidies at all will be necessary within the next 20 to 30 years.
      I have reduced the cost of the policy by 1.5% every year in real terms until 2050 where I simply assume a $20bn cost flat in real terms as no major incentive policy should be necessary anymore given current trends. Assuming a 3% discount rate the cost of the policy for 87 years is not $20 trillion anymore, nor $8 trillion, but $5.6 trillion in todays dollar, that is 1/3 of EU's current GDP: not that bad for a policy planned for a century and designed to save the planet!

      Your assumptions, not taking account discounting rate and the reduction of policy cost given current trend in susbsidies price seem very simplistic don't you think?

    3. CommentedBertrand Monin

      Thanks for your clarifications Stephan Rahmstorf.

      I sometimes have the uncomfortable impression that Project Syndicate's readers often have more intellectual probity than some of its columnists on various "fractious" issues. It is a pleasure to share the reading of an article with a community of readers who cares for accuracy and honesty, even if the columnist does not fully share this concern.

    4. Portrait of Stefan Rahmstorf

      CommentedStefan Rahmstorf

      <p>Stick to the facts: In a regional chapter on Asia in Working Group 2 (climate impacts) of the 4th IPCC report, written by authors from the region, it was erroneously stated that 80% of Himalayan glacier area would very likely be gone by 2035. This was of course not the proper IPCC projection of future glacier decline, which is found in the Working Group 1 report (which is the one about basic climate science, including the future projections of climate change). There we find a 45-page, perfectly valid chapter on glaciers, snow and ice (Chapter 4), with the authors including leading glacier experts (such as my good colleague Georg Kaser from Austria, who first discovered the Himalaya error in the WG2 report). There are also several pages on future glacier decline in Chapter 10 (“Global Climate Projections”), where the proper projections are used e.g. to estimate future sea level rise. So the problem here is not that the IPCC’s glacier experts made an incorrect prediction. The problem is that a WG2 chapter, instead of relying on the proper IPCC projections from their WG1 colleagues, cited an unreliable outside source in one place. Fixing this error involves deleting two sentences on page 493 of the WG2 report. This was an unfortunate citation error by the WG2 colleagues from Asia, but it was not based on an incorrect prediction by the IPCC climate scientists, as you well know.</p>

    5. Portrait of Stefan Rahmstorf

      CommentedStefan Rahmstorf

      <p>Stick to the facts: the IPCC does in fact give as its best estimate all of the warming since 1950 is caused by humans. The natural contributions are estimated to be about zero and constrained to be within -0.1 and +0.1 °C for both internal and externally forced natural variability. That is why the IPCC writes in the Summary for Policy Makers (available at "It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century."
      I wonder why you keep downplaying the serious risk that global warming poses to human civilisation, even to the extent of distorting to your readers what the IPCC (i.e. the scientific community at large) finds.</p>

        Portrait of Bjørn Lomborg

        CommentedBjørn Lomborg

        Dear Stefan.
        Your claim is simply wrong. The IPCC does not claim that *all* warming is due to humans. They say it is above 50%. This is *exactly* why they say "human influence has been the dominant cause of the observed warming since the mid-20th century." (Dominant meaning more than half the cause.) If they believed that humans were the full reason, they would have written 'human influence is the only cause of the observed warming since the mid-20th century.' Pls don't misrepresent the science.
        If you want, you can read the IPCC summary, where they actually explain what they mean with 'dominant' in the very next sentence: "It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together."
        "More than half" -- not all of it. Or as I wrote: "humans have caused more than half of the global rise in temperature since 1950."

    6. Portrait of Stefan Rahmstorf

      CommentedStefan Rahmstorf

      <p>Stick to the facts: the IPCC writes about sea level in its Summary for Policy Makers (available at
      "For RCP8.5, the rise by the year 2100 is 0.52 to 0.98 m".
      (RCP8.5 is a scenario with unmitigated rise in greenhouse gas emissions.)
      For the lowest emissions scenario RCP2.6 (which involves drastic emissions reductions starting in a few years and leading to zero global emissions by 2070, after that active removal of CO2 from the atmosphere) the best estimate sea-level rise by the year 2100 given by IPCC is 44 cm. </p>

    7. CommentedJeffrey Scofield

      There tends to be a focus on atmospheric global warming and little discussion of oceanic warming or ocean acidification. Since carbon in the ocean is captured for a longer timeframe than the atmosphere, thus failure to reduce CO2 levels now will elevate acids in the ocean for a very long time, I'd like to see more attention from Mr. Lomborg addressing this concern. Coral reef ecosystems and fisheries industries are almost always left out of the discussion of the importance of immediate action. Research in future technologies doesn't address the amount of waste and inneficient we are partaking in at the present.

    8. CommentedFernando Herrero Sin

      Why don't you weigh the cost of inaction against the cost of over-caution?
      Yes, much more investment in research and development (and much more in deployment -which is what actually boosts scale) of green technologies is needed. Yet, much more prescient is an unmistakable assertiveness to decarbonize the world energy system. Articles such as this one are not productive in this regard. On the contrary, articles that question the legitimacy of climate scientists' claims fuel climate skeptics' agendas and buy time to fossil-fuel-intensive industries. We need to understand that given that the science is not yet perfectly capable to describe the human-climate system, the embedded uncertainty of the risks associated with climate change can only add urgency to decarbonization.

        Portrait of Bjørn Lomborg

        CommentedBjørn Lomborg

        Dear Fernando Sin. Thanks for your comment. The cost of action vs cost of inaction comparison is a red herring, because it does not compare what we can actually achieve (the outcome of the action is almost the same as the outcome of inaction even on a 50-75yr scale, because of long lag times in the climate system).
        Take a look at my argument here:

    9. CommentedAndrew Urban

      “….the rigid orthodoxy of modern environmentalism” is the phrase that jumped out when I read Robert Stone’s Director’s Statement prior to the Australian release of his Sundance-selected doco, Pandora’s Promise. The most important aspect of Stone’s film is that it is a record of high profile, articulate and opinion-driving activists having unlocked, opened and changed their minds, escaping that rigid orthodoxy. Would this happen more often, more broadly, so as to enable a rational debate on the best ways to replace fossil fuels with renewable, clean and endless supplies. The divisive 'believers' v 'deniers' climate of debate is destructive and damages democracy.

    10. CommentedBrian Thomson

      There are a few things we need to consider that the article does not address. First, the cost of renewable energy, especially solar and wind, have fallen precipitously over the last decades. This was only partially the result of R&D, a much larger part of the fall in prices was from what engineers call "learning by doing." In other words, as we build more solar panels, we get better at building them.

      This combined with economies of scale (the millionth solar panel is cheaper to build than the first solar panel) is making solar and wind more affordable than ever. Taken together, learning by doing and economies of scale mean that a research only approach would not drive down prices as quickly as policies that actually install more renewable energy.

      The second thing that we should consider is called the "locational marginal price of electricity." In a nut shell, electricity transmission lines suffer from congestion, just like roads do. But just like roads, congestion is only present during peak use; Look at any highway at 3AM and it is empty. By distributing energy generation (think rooftop solar) close to where it will be consumed, we are reducing the need to invest in transmission wires that are only used for a few hours of peak energy use per year. this comes at considerable cost savings.

      This brings me to a third point. Since solar is a very good peak generator, comparing its costs with the average cost of electricity is not fair. Solar should be compared with other peak generators, which are always more expensive than the average. Fossil fuel peaker plants are not necessarily cheaper than using solar to generate peak energy.

      Think I am a hippie? Well, don't take my word for it, the electric industry is catching on. Xcel Energy, one of the largest utilities in the united states recently told the Colorado Public Utility Commission, "Based on generation needs, the most reliable and most cost-effective resources happen to be solar and wind. We are not [advocating more] solar because we have to, but because it is cost-effective and economical." This is just the latest in industry recognition that renewables are cost competitive, reliable, protect human health, and ensure a stable climate.

      This means that

    11. CommentedStamatis Kavvadias

      When the author reaches his conclusions, the objectivity of the whole article comes to question!

      What is so excessive about $250 billion annually for the EU? It amounts to about 1.1% of its current aggregate GDP (~16.5 trillion euro -- not dollars), which will diminish as a percentage considering the growth in 87 years. What is so strange for $20 trillion in 87 years????? Estimating current global GDP conservatively at 70 trillion, and assuming no growth (which is impossible), 20 trillion amount to *less than* 3.3‰ of the cumulative world GDP for 87 years! And that would accomplish transition to clean and more sustainable energy, and the associated improvement in the quality of life of every living soul on the planet, for 87 years!!!

      Clearly, there are no real arguments in the author's perspective.

        CommentedStamatis Kavvadias

        I understand now you said the article quantifies "the benefit of the reductions". Does it take into account all possible benefits? Namely, does it include reduction of natural disasters? Anyway, thanks for your article.

        CommentedStamatis Kavvadias

        Thank you for your answer.
        I suppose, the estimates in the article (I could not find a free version and it does not use easily understandable metrics) would not include benefits because of reduction of natural disasters, (there is only 21% certainty they are man made in the upcoming IPCC report), would they? Anyway, $250 billion for EU may be a lot (it almost completely absorbs an average GDP growth of 1% over 87 years), but the question should also be whether it is enough.

        Instead of addressing only one side of these questions, I would ask a different question: how much of the effects to which climate change possibly contributes can be avoided by CO2 reductions? This question does not mask costs and benefits and is much more important anyway!

        Portrait of Bjørn Lomborg

        CommentedBjørn Lomborg

        Dear Stamatis Kavvadias.

        Thanks for your comments. You are of course welcome to think that $250bn for virtually no impact is a bargin (incidentally, Connie Hedegaard agrees with you,, but I doubt most Europeans would appreciate their money spent in this way.

        Also, if you look at, it estimates the benefit of the reductions (the avoided climate damage) at 3% pure discount rate is €7.1bn -- this means that for each euro spent, we have avoided €0.03 in damages.

        This, I would argue, is the definition of a bad investment.

        CommentedStamatis Kavvadias

        I made a mistake for EU GDP: it is a bit more than $16.5 trillion (not euros). So, my calculation is slightly wrong for EU. $250 trillion amount to ~1.5% of aggregate GDP, to be accurate.

        CommentedStamatis Kavvadias

        To put $250 billion in perspective, it is about the current size of Greek GDP, after 3 and a half years of austerity.

    12. CommentedJan Kjetil Andersen

      Thank you for an overall good article, but where do you get the cost of EU’s climate policy to come to $250 billion annually.

      I think the cost can be estimated in many ways, but one fair way to do it is to compare it with buying carbon credits. After all, an alternative to domestic reductions is to buy carbon credits.

      The carbon credits for the obligation from the Kyoto agreement is far cheaper than 250 billion annually.

        Portrait of Bjørn Lomborg

        CommentedBjørn Lomborg

        Dear Jan Kjetil Andersen.

        Thanks for your comment. The cost of $250bn comes from this paper:; which uses the average of 5 different climate-economic models to estimates the gdp loss to the EU economy at about €209bn (or about $250bn).

    13. Commentedm r

      It is often said that those who have no "solutions" for the problem they countenance, they insist that a "Ministry" (here: Research and Development) be established to solve the deemed problems. So it is not right that the author demeans "ALL" the efforts taking place round the world, howsoever expensive OR little, just because they seem so to his own intellectual agenda.
      Something is always better than nothing, even if wrong.
      The author could well do to enter the fray and say which "levers", if there be any he would like twisted and turned to achieve his utopia and expose himself thereby to be damned. We may then get a better input from him.