Ken Caldeira is a scientist with the Carnegie Institution for Science's Department of Global Ecology. His views on climate change and geoengineering are often misrepresented by the press as favoring inaction on greenhouse gas reduction. (His actual views are seen in the quotations below and at greater length in an Oct 2009 interview.)
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.
- "Carbon dioxide is the right villain, insofar as inanimate objects can be villains." 
- "We need to eliminate CO2 emissions — about this there is no question in my mind. ... I do not see [geoengineering] as an alternative to CO2 emissions reductions, but it may be something we need to do to, for example, prevent great ice sheets from sliding into the ocean. ... When a patient is brought into the intensive care unit, doctors try to stabilize blood chemistry to avoid additional organ failure while trying to resolve the fundamental causes of those blood chemistry imbalances. We may at some point find that we need to bring our planet into the intensive care unit. Obviously, we need to work, by eliminating CO2 emissions, to keep our planet out of the ICU, but things have progressed far enough to make me question whether we will be sufficiently successful in this endeavor."
- In 2007, Caldeira said "When the s-- really hits the fan--when huge droughts in the Midwestern breadbasket are collapsing our agriculture system, ice sheets are melting, sea levels are rising, and we're getting hit by Katrina-scale hurricanes--geoengineering might be an emergency backup system we could deploy. We should avoid geoengineering if possible, but we need it in our toolbox in case of catastrophe."
In a 2008 Associated Press "climate conference footprint" article, Caldeira's skeptical comments about carbon offsets were used to bolster the story's anti-conference message, a message Caldeira termed "pernicious":
"I think this whole line of argument about how much greenhouse gas emissions come from conferences about greenhouse gas emissions reduction is pernicious. ... The success of the summit is far more important than any CO2 that might be emitted traveling to or from the summit." 
Caldeira's geoengineering recommendations have been covered without noting that he considers geoengineering to be an emergency measure, not a cure:
- One blogger noted an omission in an NPR geoengineering report: "NPR has a brief piece on geo-engineering, also focusing on the sulfate aerosol flavor, including some quotes from Ken Caldeira among others that likewise makes no mention of ocean acidification.... [yet] Caldeira ...[has] been doing a lot of work on ocean acidification"; Caldeira responded in a comment, explaining that he views geoengineering as an "intensive care unit" intervention.
- In their 2009 book SuperFreakonomics, Steven Levitt and Stephen Dubner mischaracterized Caldeira as advocating geoengineering in place of reducing greenhouse gas emissions, falsely saying "his research tells him that carbon dioxide is not the right villain in this fight.". Caldeira subsequently changed his home page to include the "CO2 is the right villain" quote, and in an interview went further, stating:
"the actual statements attributed to me are based on fact, but the contexts and the framing of those issues are very different from the context and framing that I would put those same facts in...So I think that the casual reader can... come up with a misimpression of what I believe and what I feel about things."
- Jeff Goodell (2009-11-21). Geoengineering the Planet: The Possibilities and the Pitfalls. Yale Environment 360. Retrieved on 2009-11-22.
- "The Darkening Sea http://www.newyorker.com/archive/2006/11/20/061120fa_fact_kolbert The New Yorker" (20 November 2006). Retrieved on 2008-10-24.
- Final Prospectus for Synthesis and Assessment Product 2.2, Biography: Ken Caldeira (updated 14 February 2006) http://www.climatescience.gov/Library/sap/sap2-2/sap2-2prospectus-final-caldeira.htm, Retrieved on 2008-10-24
- Ken Caldeira on his Intellectual Ventures ties (2009-10-19). Retrieved on 2009-10-19.
- "When Being Green Raises the Heat http://www.nytimes.com/2007/01/16/opinion/16caldeira.html", The New York Times (16 January 2007). Retrieved on 2008-10-24.
- "How to Cool the Globe http://www.nytimes.com/2007/10/24/opinion/24caldiera.html", The New York Times (24 October 2007). Retrieved on 2008-10-24.
- "New Study Warns of Total Loss of Arctic Tundra http://www.nytimes.com/2005/11/01/science/earth/01cnd-climate.html", The New York Times (1 November 2005). Retrieved on 2008-10-24.
- Ken Caldeira. Caldeira Lab Home Page. Retrieved on 2009-11-19.
- Ken Caldeira. Caldeira explains views in a comment. Retrieved on 2009-11-19.
- Brad Johnson (2009-11-17). Ken Caldeira Contradicts SuperFreaks: ‘Carbon Dioxide Is The Right Villain’. Wonk Room. Retrieved on 2009-11-19.
- Anna Haynes (2008-12-04). The AP’s climate conference footprint fetish. Grist.
- Geo-engineering and ocean acidification. TheWayThingsBreak (2009-06-17).
- Ken Caldeira (2007_06). What Corals are Dying to Tell Us About CO2 and Ocean Acidification(pdf). Oceanography.
- Joe Romm (2009-11-19). Anatomy of a debunking: Caldeira says Superfreakonomics is “damaging to me because it is an inaccurate portrayal of me” and filled with “many” misleading statements.... Climate Progress. Retrieved on 2009-11-19.
- Caldeira, pers. comm., Oct.2009
- Carnegie Institution Department of Global Ecology
- Ken Caldeira and his Carnegie lab
- U.S. Climate Change Science Program Biography of Ken Caldeira, Final Prospectus for Synthesis and Assessment Product 2.2