Longer, hotter heat waves for California

William Collins was the keynote speaker for yesterday's California Climate Change Conference. Collins is a professor at U.C. Berkeley and a senior scientist and head of the department of Climate Science at Lawrence Berkeley National Laboratory. He has a Ph.D. in astrophysics and he's conducted research on the observation and modeling of the Earth's climate system at both the National Center for Atmospheric Research and Scripps Institute of Oceanography. He is a lead author of the IPCC Assessment, Working Group I, which covered the physical science of global warming.

His talk was titled "the Future of California's Climate from a Global Perspective." (see here for the slides) He came loaded with explanatory graphics and statistics, and was suitably cautious in getting anywhere near predicting specifics, so the conclusions of his analysis were conservative. And here they are:

• Recent climate change is very likely human-induced.


• Near-term climate change before 2030:


• Western US will be noticeably warmer compared to climatology.


• Predictions converge across models and scenarios.


• This convergence could facilitate process of adaptation.


• Long-term climate change by 2100:


• Extremes include less frost, more dry spells, longer heat waves.


• Warming increases with increasing levels of atmospheric CO2.


• There are real prospects for more dynamic coupling of climate modeling, impacts, adaptation, and mitigation.