California Governor Jerry Brown used the occasion of his fourth inaugural address to propose an ambitious new clean energy target for the state: 50% renewable energy by 2030.
“We are at a crossroads,” Brown said in announcing the proposal, according to Climate Progress. “The challenge is to build for the future, not steal from it, to live within our means and to keep California ever golden and creative.”
Already the leader in installed solar...
- Ph.D., Physics, Rutgers University. 
Roger Cohen is the former Manager of Strategic Planning and Programs at ExxonMobil Corporation.
He is a George C. Marshall Institute “Expert,” and has led a push for the American Physical Society (APS) to weaken their position on climate change.
Cohen became involved in studying global warming when Exxon realized that its “business environment” could be affected. 
Stance on Climate Change
“At this point there is little doubt that the IPCC position is seriously flawed in its central position that humanity is responsible for most of the observed warming of the last third of the 20th century, and in its projections for effects in the 21st century.” 
“In 1980, a few of us in the research organization of a large multinational energy corporation realized that the climate issue was likely to affect our future business environment. We subsequently started the only industrial research activity in the basic science of climate change.” 
“So what do we really know? We Know that climate is far too complex and too insensitive to greenhouse gases to pretend that we can 'stabilize' it by marginal changes in CO2 emissions, whether it is California's AB32, or the many incarnations of national legislation or global proposals. We know that government policies offer great economic pain and no environmental gain. We also know that the global warming issue has produced intellectual deception and the subversion of the scientific process, widespread corporate rent seeking, and the gross waste of resources that could have gone to improve our environment. But we still have it within our grasp to restore integrity to the science process and to avert unnecessary economic hardship, especially for the world's poorest who might otherwise aspire to make great strides this century.” 
January 27, 2012
Cohen is one of 16 “scientists” who signed a Wall Street Journal Op-Ed titled “No Need to Panic About Global Warming.”
Other signatures include those of Claude Allègre, J. Scott Armstrong, Jan Breslow, William Happer, William Kininmonth, Richard Lindzen, James McGrath, Rodney Nichols, Burt Rutan, Harrison H. Schmitt, Nir Shaviv, Edward David, Michael Kelly, Henk Tennekes, and Antonino Zichichi.
Media transparency, who found that the article had misrepresented the position of Yale economist William Nordhaus, reported on the opinion piece here. SkepticalScience did a comprehensive examination of the signatories here.
Cohen participated in a seminar on global warming with fellow skeptic William Happer during California's vote on Prop 23, which would have suspended the “Global Warming Act of 2006.”
The seminar was arranged by Dr. Martin Fricke of San Diego, and “arranged for two experts to review aspects of the 'debate'.” Cohen's talk was critical of Michael Mann's “Hockey Stick” graph, and supposed “behind-the-scenes-manipulation” of “Climategate” (of which the scientists involved where exonerated of any wrongdoing). 
August 12, 2009
Cohen was part of a 2009 petition,  in part written by climate change skeptic William Happer , that urged the American Physical Society to change its position statement on climate change to one more skeptical of mainstream science. , 
According to a website developed to “remove or tone down the American Physical Society’s 2007 Statement on Climate Change to a less alarmist and more scientifically thoughtful statement,” respondents are urged to contact either Bob Austin or Roger Cohen to “express their response to the question, 'Should the 2007 APS Statement by scrapped and a new one developed?'”.
The new climate statement recommended by the letter includes the following:
“While substantial concern has been expressed that emissions may cause significant climate change, measured or reconstructed temperature records indicate that 20th -
21st century changes are neither exceptional nor persistent, and the historical and geological records show many periods warmer than today. In addition, there is an extensive scientific literature that examines beneficial effects of increased levels of carbon dioxide for both plants and animals.”
According to a search of Google Scholar, Cohen has co-published one article in a journal on the subject of climate change.
His article was titled “Global Warming and Carbon-Negative Technology: Prospects for a Lower-Cost Route to a Lower-Risk Atmosphere,” and published in the journal Energy & Environment (which has been criticized for its peer-review and is connected to numerous climate change skeptics).
Energy & Environment is edited by climate change skeptic Sonja Boehmer-Christiansen. According to a search of WorldCat, a database of libraries, Energy and Environment is found in only 25 libraries worldwide. The journal is not included in Journal Citation Reports, which lists the impact factors for the top 6000 peer-reviewed journals. The editor of Energy and Environment, Sonja Boehmer-Christiansen has stated that “it's only we climate skeptics who have to look for little journals and little publishers like mine to even get published.”
“Roger Cohen,” Profile at Global Thermostat. Accessed January, 2012.
Roger Cohen. “On the IPCC's Case for Anthropogenic Global Warming,” Science and Public Policy Institute, August 6, 2008. Archived March 5, 2010.
“Roger's Lyncean Text With Slides” (PDF). Retrieved from Box.com January 31, 2012 (created Aug 4, 2010).
“Scientists Challenge the Fraud and Emotionalism Behind CA’s Cap&Trade Rules,” Temple of Mut, August 5, 2010.
“An Open Letter to the Council of the American Physical Society,” The Heartland Institute (Policy Documents) August 12, 2009.
“The Happer Letter: Re-Opening the Climate Change Debate,” NewsBurglar, June 26, 2009.
“A Gaggle is Not a Consensus,” openletter-globalwarming.info. Accessed January 31, 2012.
“Regarding the National Policy Statement on Climate Change of the APS Council: An Open Letter to the Council of the American Physical Society,” openletter-globalwarming.info. Accessed January 31, 2012.
“APS Council Overwhelmingly Rejects Proposal to Replace Society’s Current Climate Change Statement,” Physics Frontline, November 11, 2009.
“Durango Herald: Roger Cohen Bets $5,000,” ClimateBet, January 28, 2008.
“Dr. Roger Cohen,” George C. Marshall Institute. Accessed January 31, 2012.