Ken Caldeira  Kenneth Caldeira is an atmospheric scientist who works at the Carnegie Institution for Science's Department of Global Ecology. He researches ocean acidification, climate effects of trees, intentional climate modification, and interactions in the global carbon cycle/climate system. He also acted as an inventor for Intellectual Ventures, a Seattle-based invention and patent company headed up by Nathan Myhrvold. 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". 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.