Green describes himself as “a free-market environmentalist,” and believes that most environmental problems stem from an absence of properly defined and enforced property rights, and/or insufficient societal wealth to afford environmental protection. He has testified that while he cherishes the environment, and believes it worth protecting such environmental protection must not come at the expense of other cardinal American values such as property rights, due process, economic freedom, individual liberty, and personal responsibility.
On climate change, Green has repeatedly observed that he believes the climate is warming, and greenhouse gases are partially responsible. He is, however skeptical of computer models that contain unsubstantiated assumptions about positive feedback loops, and he has expressed contempt for computerized projections of future or regional climate change, comparing them to “computerized horoscopes.” Green has testified that as no technology currently exists to significantly and affordably reduce greenhouse gas emissions in the near term, he favors an agenda of adaptation and resilience-building. To hedge against the risk of more extreme climate change, Green favors increased research into geoengineering.
With regard to energy policy, Green considers himself an “energy realist,” and does not believe there are, at present, technologies that can substantially or affordably substitute for conventional energy sources such as coal, nuclear power, oil, and natural gas. To the extent that such alternatives do exist, Green has shown they pose environmental and economic challenges, and should not be hastily adopted without due regard to the potential for adverse and unintended consequences.