We need to put a price on carbon, and that's what cap-and-trade does and that's also what a CO2 tax does. As long as our current valuation in the marketplace tells us every minute of every day that it's perfectly all right to dump 90 million tons of global warming into the thin atmosphere surrounding the planet every 24 hours as if that atmosphere is an open sewer, then the individual actions are not going to solve the problem.

The climate, financial and national security crises are all connected. They share the same cause: Our [the USA's] absurd dependency on foreign oil. As long as we need to spend billions of dollars each year to buy foreign oil from state-run oil companies in the Persian Gulf, our problems of a trade deficit, a budget deficit and a climate crisis will persist.

The scientific evidence of how serious this climate crisis is becoming continues to amass week after week after week.

Global warming is real and human activity is the main cause. The consequences are mainly negative and headed toward catastrophic, unless we act. However, the good news is that we can meet this challenge. It is not too late, and we have everything we need to get started.

Most people in politics draw energy from backslapping and shaking hands and all that. I draw energy from discussing ideas.

Adopting a central organizing principle means embarking on an all-out effort to use every policy and program, every law and institution, to halt the destruction of the environment.

A majority of Trump's voters were in favor of staying in the Paris Agreement. And if you look at what's really happening in the economy, the economic argument actually is very strongly in favor of the Paris Agreement. There are now twice as many jobs in the solar industry as in the coal industry. Solar jobs are growing 17 times faster than other jobs in the U.S.