We cannot afford to put off change any longer. We have to get on a new path within this new administration. We have only four years left for Obama to set an example to the rest of the world. America must take the lead.

Injection of environmental and political perspectives in midstream of the science discussion cannot help the process of inquiry. I believe that persons with relevant scientific expertise should concentrate, with pride, on cool objective analysis, providing information to the public and decision-makers when it is found, but leaving the moral implications for later common consideration, or at most for summary inferential discussion.

Politicians think that if matters look difficult, compromise is a good approach. Unfortunately, nature and the laws of physics cannot compromise - they are what they are.

...99 percent confident that the world really was getting warmer and that there was a high degree of probability that it was due to human-made greenhouse gases.

We have at most ten years—not ten years to decide upon action, but ten years to alter fundamentally the trajectory of global greenhouse emissions.

Imagine a giant asteroid on a direct collision course with Earth. That is the equivalent of what we face now with climate change, yet we dither.

The carbon emissions from tar shale and tar sands would initiate a continual unfolding of climate disasters over the course of this century. We would be miserable stewards of creation. We would rob our own children and grandchildren.