David Archer uses computer simulations to understand the balance between carbon dioxide levels in the oceans and in the atmosphere in the past to better predict the impact that changing levels will have on future climate. He is a contributor to Realclimate.org, where commentary written by working climate scientists can be accessed by journalists and the public. Archer is the author of The Long Thaw: How humans are changing the next 100,000 years of Earth's climate (Princeton University Press, 2008), which earned him the 2009 Walter P. Kistler Book Award. He also is the author of an undergraduate textbook for non-science majors, titled Global Warming: Understanding the Forecast.