The Next Problems:I am about to start to teach my climate change class for the fourth time. When I started teaching this course I did not know what to expect. I went into the course thinking that the discourse needed to change. Most of the conversations that I heard were about Kyoto, and often the conversation was about the Bush administration’s failure to sign the
Kyoto Protocol. There was this idea that if the U.S. signed the Kyoto Protocol, then the climate problem would be solved. There was this idea that the solution resided in some movement of federal policy.
What struck me was that all of the conversations were polarized – this or that. Similarly they were stunningly simplistic. I found that the general knowledge about climate change was quite high. In fact, with regard to the knowledge of the Earth’s climate as a whole, the non-scientists in my class often knew more than the scientists. Therefore, it was not a lack of knowledge of the climate that was the issue. It was the realization that the climate change problem is completely intertwined with society. There was climate and policy, climate and energy, climate and public health, climate and agricultural, climate and this and that. And all of these issues are related, and climate and energy are, today, completely correlated, and energy use is at the core of economic success. It’s a complex problem. It’s a problem motivated by science, but once past the motivation, science comes into relation with all of these other interests. Often science does not bring immediacy to it all. We are faced with this enormous, long-term environmental problem, wrapped up with the immediacy of energy security and at the whim of markets and the economy.
We are at a governmental transition that, with respect to science (not just climate science), looks to be about as different as it can be. People are positioning themselves, planning for what might be and what they might want to be. With that, I want to return to the science, and what are the science issues that are evolving as the most consequential.
Here is my list:
1) Land (and sea) ice is melting faster than predicted in the IPCC Assessment Report 4. This is due to the over simplification of the melting of ice in previous models. Rignot, E. and P. Kanagaratnam, 2006: Changes in the velocity structure of the Greenland ice sheet. /Science/.
Rignot, E. and K. Steffen, 2008: Channelized bottom melting and stability of floating ice shelves. /Geophysical Research Letters/.
2) Because of the underestimation of ice melt, sea level rise has been underestimated. We are committed to sea level rise, and we need to plan accordingly.Shepherd, A. and D. Wingham, 2007: Recent sea-level contributions of the Antarctic and Greenland ice sheets. /Science/.
Horton, R., C. Herweijer, C. Rosenzweig, J. P. Liu, V. Gornitz, and A. C. Ruane, 2008: Sea level rise projections for current generation CGCMs based on the semi-empirical method. /Geophysical Research Letters/.
3) The terrestrial and ocean sinks of carbon dioxide are likely to be less effective than previously stated. (Be on the look out for a new paper by Jorge Sarmiento.)Behrenfeld, M. J., R. T. O'Malley, D. A. Siegel, C. R. McClain, J. L. Sarmiento, G. C. Feldman, A. J. Milligan, P. G. Falkowski, R. M. Letelier, and E. S. Boss, 2006: Climate-driven trends in contemporary ocean productivity. /Nature/.
Polovina, J. J., E. A. Howell, and M. Abecassis, 2008: Ocean's least productive waters are expanding. /Geophysical Research Letters/.
4) The acidification of the ocean is likely to be more disruptive sooner than expected.J. Timothy Wootton, Catherine A. Pfister, and James D. Forester, 2008: Dynamic patterns and ecological impacts of declining ocean pH in a high-resolution multi-year dataset, /Proceedings National Academy of Sciences/.
Orr, J. C., V. J. Fabry, O. Aumont, L. Bopp, S. C. Doney, R. A. Feely, A. Gnanadesikan, N. Gruber, A. Ishida, F. Joos, R. M. Key, K. Lindsay, E. Maier-Reimer, R. Matear, P. Monfray, A. Mouchet, R. G. Najjar, G. K. Plattner, K. B. Rodgers, C. L. Sabine, J. L. Sarmiento, R. Schlitzer, R. D. Slater, I. J. Totterdell, M. F. Weirig, Y. Yamanaka, and A. Yool, 2005: Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. /Nature/.
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Given our poor representation of the physics of melting in land ice, abstracting this to a tendency to underestimate changes that are associated with phase changes of water, melting of permafrost and release of greenhouse gases stored in permafrost is likely to be underestimated.
We must pay increased attention to adaptation. There is no reason to believe that we can mitigate our ways out of the above. We need to develop the capability to do Climate Impact Assessments for both 'geo-engineering" and the geo-engineering that we will do because of energy policy and land-use and the vagaries of billions of people. This leads to a type of modeling that is different from the type of modeling that most scientists advocate.
As I have stated before, our knowledge of climate change gives us unprecedented knowledge of the future. We have opportunity. We have responsibility.
Thanks for all of the feedback from this blog, and I am looking forward to the next year.
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