Ken Caldeira

Among Caldeira's key contributions to science are his relatively early recognition of the threats posed by ocean acidification, his pioneering investigations into the environmental consequences of intentional intervention in the climate system ("geoengineering"), and the first peer-reviewed study to estimate near-zero-emission energy needs consistent with a 2 °C climate stabilization target. He has also played a central role in helping to elucidate what our understanding of long-term geochemical cycles implies for the fate of today's carbon dioxide emissions. Caldeira served as a member of the committee producing the 2015 U.S. National Academy of Sciences report "Geoengineering Climate: Technical Evaluation and Discussion of Impacts". He is also a contributing author to the Intergovernmental Panel on Climate Change (IPCC) AR5 report Climate Change 2013: The Physical Science Basis. In 2010, he was a co-author of the 2010 US National Academy America's Climate Choices report, and was elected Fellow of the American Geophysical Union. He participated in the UK Royal Society geoengineering panel in 2009 and ocean acidification panel in 2005. Caldeira was coordinating lead author of the oceans chapter for the 2005 IPCC report on Carbon Capture and Storage.

In 2013, with other leading experts, he was co-author of an open letter to policy makers, which stated that "continued opposition to nuclear power threatens humanity's ability to avoid dangerous climate change."

Caldeira's work was featured in a 14 May 2012 article in The New Yorker, entitled "The Climate Fixers" and in a 20 November 2006 article in The New Yorker, entitled "The Darkening Sea." In 2007, he contributed two op-ed pieces on the subject of global warming to The New York Times.

In 2011, Caldeira resigned as a lead author of an IPCC AR5 chapter, stating "Again, I think the IPCC has been extremely useful in the past, and I believe the IPCC could be extremely useful in the future. [...] My resignation was made possible because I believe that the chapter team that I was part of was on the right track and doing an excellent job without my contribution. Had I had a scientific criticism of my chapter team, you can be assured that I would have stayed involved. So, my resignation was a vote of confidence in my scientific peers, not a critique."

In the 1980s, Caldeira worked as a software developer. He received his Ph.D in Atmospheric Sciences in 1991 from the New York University Department of Applied Science. From 1991 to 1993, Caldeira worked at Penn State University as a post-doctoral researcher. He then worked as an Environmental Scientist and Physicist at Lawrence Livermore National Laboratory until 2005, when he began his current position at the Carnegie Institution: Department of Global Ecology. He was named a "Hero Scientist of 2008" by New Scientist magazine and listed as number 36 out of 100 Agents of Change in Rolling Stone magazine's 2 April 2009 list of 100 "artists and leaders, policymakers, writers, thinkers, scientists and provocateurs who are fighting every day to show us what is possible." Bill Gates, in his 2016 end-of-year blog post, referred to Ken Caldeira as "my amazing teacher".

Caldeira has argued for a policy goal of zero carbon dioxide emissions. In 2005, he said, "If you're talking about mugging little old ladies, you don't say, 'What's our target for the rate of mugging little old ladies?' You say, 'Mugging little old ladies is bad, and we're going to try to eliminate it.' You recognize you might not be a hundred per cent successful, but your goal is to eliminate the mugging of little old ladies. And I think we need to eventually come around to looking at carbon dioxide emissions the same way.". In 2014, he said, "It is time to stop building things with tailpipes and smokestacks. It is time to stop using the sky as a waste dump for our carbon dioxide pollution."