Gavin Schmidt, NASA/Goddard Institute for Space Studies

Topic: "What are climate models good for?"  (Video)


"If we had observations of the future, we obviously would trust them more than models, but unfortunately observations of the future are not available at this time." (Knutson and Tuleya, 2005)

Climate change is ongoing, and trying to explain what is happening now, and what might happen in the future are key tasks that require large-scale complex climate models of the atmosphere, ocean, land surface and cryosphere. But how well do such models perform? Can they predict climate changes in the face of the chaotic dynamics of weather? How have they performed so far? I will discuss how the credibility of model results can be established and what are the current limitations. This involves assessing short term climate variability, the response of the climate system to external factors (such as variability of the sun or large volcanic eruptions), paleo-climate information and how model-data discrepancies get resolved. I will (hopefully) demonstrate that while climate models are by no means perfect, they can be very useful.