Better Model, Less Warming
This is the central claim of paper recently published in the Journal of Science and discussed at length by Patrick Michaels in his monthly column The Current Wisdom.
The paper, published by Masahiro Watanabe and his colleagues, improves the MIROC (Model for Interdisciplinary Research on Climate) model. The updated version, MIROC5, will be used in the 5th Assessment Report of the United Nations Intergovernmental Panel on Climate Change, which is due in 2013.
“Watanabe et al. report that the climate sensitivity is now 2.6°C (4.7°F) – more than 25% less than in the previous version on the model.”
Why the change in predicted warming?
The change resulted from a more realistic simulation of the way clouds work, resulting in a major reduction in the model’s “climate sensitivity,” which is the amount of warming predicted for a doubling of the concentration of atmospheric carbon dioxide over what it was prior to the industrial revolution.
Michaels also notes that all models are imperfect, and thus
such improvements will continue into the future as both our scientific understanding and our computational abilities increase.
Will this lead to an even greater reduction in climate sensitivity and projected temperature rise? There are many folks out there (including this author) that believe this is a very distinct possibility, given that observed warming in recent decades is clearly beneath the average predicted by climate models. Stay tuned!
And you should stay tuned—both to the Civil Society Coalition blog and to The Current Wisdom.
Published monthly, The Current Wisdom is written by Patrick J. Michaels, Ph.D. in ecological climatology from the University of Wisconsin at Madison and Senior Fellow at the Cato Institute. His highly-informative columns comment exclusively on peer-reviewed scientific literature. To follow The Current Wisdom, visit the Cato@Liberty blog.