James Hansen, a former top NASA scientist; Ken Caldeira, of the Carnegie Institution; Kerry Emanuel, of the Massachusetts Institute of Technology; and Tom Wigley, of the University of Adelaide in Australia signed the letter.
AP reported that the four addressed the idea that renewable energy alone is all that's needed - or that should be used - to stop climate change:
“Those energy sources cannot scale up fast enough” to deliver the amount of cheap and reliable power the world needs, and “with the planet warming and carbon dioxide emissions rising faster than ever, we cannot afford to turn away from any technology” that has the potential to reduce greenhouse gases.
[The scientists] aren’t opposed to renewable energy sources but want environmentalists to understand that “realistically, they cannot on their own solve the world’s energy problems.”The New York Times' Andy Revkin has posted this excellent blog post containing the text of the scientists' letter and further thoughts, including the "tough realities" facing nuclear power - and alternative energy sources.
These four scientists have long shown courage in their work, and in raising the nuclear power taboo, they have done so again. The world is facing climate disaster, and it's "five minutes to midnight." Yet globally over 1.3 billion people are without access to electricity and 2.6 billion people are still without clean cooking facilities.
Are we capable of developing and implementing non-ideological, fact-based, realistic, and pragmatic strategies to meet the world's energy needs and cut carbon emissions by at least 80% by the middle of this century? It starts with a fearless asking of all the questions that need to be considered.
Nov. 12 Update: Read this excellent blog post by the Union of Concerned Scientists' Steve Clemmer that comes down solidly on the side of renewables.