Steven E. Koonin, once the Obama administration’s undersecretary of energy for science and chief scientist at BP, stirred up a swirl of turbulence in global warming discourse this week after The Wall Street Journal published “Climate Science is Not Settled,” his essay calling for more frankness about areas of deep uncertainty in climate science, more research to narrow error ranges and more acknowledgement that society’s decisions on energy and climate policy are based on values as much as data. (The Journal seems to keep this headline on file; here’s a 2009 essay, “Climate Science Isn’t Settled,” by the M.I.T. climatologist Richard Lindzen.)
Predictably, the piece by Koonin, who became the founding director of New York University’s important Center for Urban Science and Progress in 2012, was quickly hailed by fossil fuel defenders. At the same time, some of Koonin’s central points about the state of climate science were sharply challenged by climate scientists and climate campaigners. I was on the run at the time but sent Koonin a couple of questions, which I also posted on Tumblr.
Here they are with his answers (with some email shorthand cleaned up), along with a fresh critique of Koonin’s argument by a group of climate science and policy researchers associated with Carnegie Mellon University and a final thought from me:
Q.Your piece makes the important point that, on vital questions, there’s enduring deep uncertainty behind the “97 Percent of Climate Scientists Agree” headlines and Intergovernmental Panel on Climate Change report summary language. That was the point of my pieces on the many “shapes” of climate knowledge.
But I think your piece implies too much that further scientific inquiry can improve the picture. On regional forecasting, extremes (hurricanes), sensitivity to doubled CO2, and other key questions, further science — if anything — has clarified that some of these uncertainties aren’t going anywhere.
A.I agree that regional and extremes are probably hopeless. But I would suppose that equilibrium climate sensitivity [background] and even global mean surface temperature on a decadal scale could be better nailed down by model pruning and better ocean data. An interesting way to test that (which I don’t think has ever been done, but don’t know for sure) is to assume one of the models is the truth, downscale the sampling of the data to what we might reasonably observe in the real world, and see to what extent that can be used to recover the truth. The results would give some indication of the extent to which more observations would help.
Q.You also imply that you can’t have “good” climate policy in the face of deep persistent uncertainty. In other endeavors, society has figured this out and some sustained inquiry is going into how to take a least-regrets policy on the greenhouse buildup. See the World Bank paper on “Investment Decision Making under Deep Uncertainty – Application to Climate Change.”
A.This is indeed implied by the tagline [“We are very far from the knowledge needed to make good climate policy”], which I didn’t write or even see until publication. As I hoped to imply in the last few paragraphs of the article, we can get to good climate policies, but they will depend as much (or even more) upon “values” than upon science, given the latter’s uncertainties.
Here’s the open letter written by nine scientists affiliated with the Center for Climate and Energy Decision Making at Carnegie Mellon (their :
Uncertainty in Climate Science: Not an Excuse for Inaction.
On Sunday, more than three hundred thousand people marched in New York City and around the world to urge governments to support an agreement to reduce emissions of greenhouse gases that cause climate change. Then, on September 23, the United Nations Secretary-General Ban Ki-moon hosted the 2014 UN Climate Summit. There is hope that this meeting will catalyze leadership support for an agreement that enables a pathway to avoid large impacts from climate change.
While the world waited for these events to unfold, on September 20 the Wall Street Journal published an editorial titled “Climate Science is Not Settled.” In this editorial, Steve E. Koonin, Undersecretary for Science in the Department of Energy during President Barack Obama’s first term and current director of the Center for Urban Science and Progress at New York University, argued that while there is agreement that the climate is changing, there is no scientific agreement about the implications of climate change. Further, he suggests that existing climate models are unable to provide accurate predictions of future climate. Reading the editorial leaves the impression that we don’t have enough information to make decisions about climate change and that we should focus our efforts “to make climate projections more useful over time.” As scientists and decision-makers working on many fronts of the climate change problem, we believe this is a dangerous message. We are writing this response in order to highlight our concerns and lend our voices to support the 2014 U.N. Climate Summit.
In his editorial Dr. Koonin states in categorical terms that climate is changing, and that burning fossil fuels is the cause. We highlight that when climate scientists say the science is “settled,” that is precisely what we mean – no more and no less. When a sitting senator calls climate change science a “hoax,” it is no wonder that climate scientists need to stress that the fundamentals are settled. Indeed, the fundamentals of carbon dioxide and the greenhouse effect were well understood in the 19th century. Dr. Koonin also acknowledges that the IPCC reports describe the limitations associated with climate models. However, he fails to discuss how, even though the detailed results may vary, all of these climate models indicate our emissions of greenhouse gases will have a substantial effect on the climate system in the coming decades. We do not argue that we have complete certainty about the implications of such warming. We argue we have enough information to warrant action.
Climate skeptics often argue that, during the last fifteen years, global temperatures have been nearly flat and that climate models are unable to predict or explain this pattern. This so-called “climate hiatus” rears its head again in Dr. Koonin’s editorial. In fact, these last fifteen years are in no way surprising: 1998 was an extremely hot El Niño year and the early 2000s were at the peak of a strong solar cycle. The remarkable thing is that global temperatures have remained close to the peak values of the late 1990s despite the fact that natural sources of variability would indicate that they should have cooled. A statistical model (based on the work of Judith Lean at the Naval Research Laboratory) that accounts for solar variability, El Niño, volcanic activity, and greenhouse warming indicates that the underlying trend of global warming has accelerated over the past 15 years.
We are further baffled by Dr. Koonin’s implication that climate feedbacks are so complicated that there might be some negative feedback that makes the whole thing go away. Yes, the detailed physics of feedbacks are uncertain, but understanding isn’t just based on theory or recent history. The geological record is filled with evidence that feedbacks (mostly water vapor, some others) will amplify the intrinsic greenhouse signal, and we are not aware of any evidence to support the notion that a “white knight” negative feedback will make this all go away.
Dr. Koonin is correct that there is still uncertainty about the magnitude of the impacts of climate change and society will have to make decisions under such uncertainty. He seems to suggest, however, that there is enough scientific uncertainty that we can’t even claim that the impacts of climate change will cause harm. Further, he seems to imply that we should limit our efforts to “no regrets” alternatives such as “accelerating the development of low-emissions technologies and in cost-effective energy-efficiency measures.”
The detailed impacts of climate change remain uncertain. However, every comprehensive assessment of climate change impacts points to serious disruptions ahead. Given that ecosystems and human society have evolved to adapt to the current climate, it can hardly be otherwise. Even the “lower bound” on climate change impacts will cause harm. Moreover, the costs of climate change mitigation are controllable and can be phased in gradually with intelligent policy instruments. Dr. Koonin suggests that “the crucial, unsettled scientific question for policy is, how will the climate change over the next century under both natural and human influences?” We propose that the crucial question for climate policy is what are policy actions we should undertake now in the face of these uncertainties. This will not be the first time we, as a society, have to make difficult decisions under uncertain conditions. And, as the Charney report to the National Academy of Sciences stated 35 years ago, “a wait and see policy may mean waiting until it is too late.”
By: Peter Adamsα, Neil Donahueα, Michael Dworkinβ, W. Michael Griffinα, Klaus Kellerα,δ, Ines Azevedoα, Paulina Jaramilloα, Constantine Samarasϕ, and Nathaniel Gilbraithα.*
αDepartment of Engineering and Public Policy. Carnegie Mellon University,
βInstitute for Energy and the Environment. Vermont Law School
δDepartment of Geosciences. The Pennsylvania State University
ϕDepartment of Civil and Environmental Engineering. Carnegie Mellon University
*The authors are affiliated with the Center for Climate and Energy Decision Making of the Department of Engineering and Public Policy at Carnegie Mellon University. The views and opinions in this essay are the sole responsibility of the authors and do not represent institutional positions.
I heartily concur with their closing thought, but also with some of Koonin’s central points.
Pressing the frontiers of climate science and related research is vital, but it’s wishful thinking to expect further science to substantially narrow uncertainties on time scales that matter when it comes to regional or short-term climate forecasting, the range of possible warming from a big buildup of carbon dioxide, the impact of greenhouse forcing on rare extremes and the like.
There’s plenty that can be done right now to advance policies attuned to today’s understanding of the building human influence on climate — along with climate’s big influence on humans — and much of that is work that everyone can agree on.
For more:
Watch Gavin Schmidt’s TED talk on climate modeling.
Please click back to David Roberts’s excellent post on deep uncertainty at Grist: “In a climate-crazed world, how can we plan for the future?”
Review Stephen H. Schneider’s many papers on uncertainty and climate policy.
Explore this 2007 Bulletin of the Atomic Scientists discussion of “The uncertainty in climate modeling.”