Some studies suggest that the Arctic Ocean may be ice-free by the end of the century.

Bloomberg's $50 million is not going to revolutionize the electric power industry. But his willingness to fight is already inspiring others to see Big Coal differently.

Bloomberg is famously impatient with beltway politics and believes that to get anything done you need to work from the ground up.

Climate scientists have long pointed to the Southwest as one of the places in the U.S. that is most vulnerable to global warming impacts, especially drought. And if there's one thing that even climate denialists don't dispute, dry things burn.

When it comes to climate and energy, Gates is a radical consumerist. In his view, energy consumption is good - it just needs to be clean energy.

In the United States, we do a pretty good job of protecting iconic landscapes and postcard views, but the ocean gets no respect.

Among all the tests President Obama faced in his first term, his biggest failure was climate change.