- Country: The United States
- Title: Adjunct Senior Fellow, Council on Foreign Relations
- Education: Harvard University, Massachusetts Institute of Technology
Lucy Berman: Why are so many seemingly respectable people convinced that global warming is not a real problem? Are they are all just cranks or political hacks, or is there really something to debate?
A: It is hard to defend the position that nothing should be done about global warming. The evidence is just too overwhelming. But informed people disagree over the severity of the problem -- in part because nobody really knows how the buildup in greenhouse gases will affect the climate system, and especially because it is hard to assess how nature and humans will respond to a changing climate.
Some people see humans, especially, as highly adaptive; that leads them to worry less about global warming. Others are more pessimistic. What really scares me about climate change are the unknown unknowns -- the possibility that the climate system will respond in radical ways and that nature will adapt poorly. The only way to reduce the odds of those extreme -- some people say "catastrophic" -- outcomes is to control the emissions that cause global warming in the first place. And if those efforts are tardy or fail, then geoengineering is a Plan B that is filled with troubles but better than nothing.
Will Rafey: Can geoengineering ever be a reliable substitute for a transition to renewable, sustainable energy?
A: Per my reply to Lucy Berman, there is no simple substitute for controlling emissions. Renewable energy could be a large part of that effort -- and surely will be -- but it is not the only option. Much higher energy efficiency must play a role; nuclear power can play a major role (if, at the same time, there is attention to controlling the risk of weapons proliferation); advanced coal-fired power plants that safely store most of their pollution underground can also play a role. Geoengineering could be, at best, a Plan B. And if we don't invest to understand it and its flaws, it won't even be Plan B.