My house is covered in solar panels, I'm a great believer in all this - we all should be doing this.

Global warming is no longer a philosophical threat, no longer a future threat, no longer a threat at all. It's our reality.

I think we need to think of lots of ways to communicate. And we tried some at 350. We organised what they called the largest art project in the planet's history. We do a lot with art and music and things.

My guess is that liberating the fossil fuel industry to frack anywhere they want will drive down the rate at which we're converting to sun and wind. And it's entirely a rate problem at this point.

The most blatant examples are increased power and frequency in hurricanes and the increased depth and frequency of heat waves.

The real negotiation is between humans on the one hand and chemistry and physics on the other. And chemistry and physics, unfortunately, don't bargain.

The models that have been constructed agree that when, as has been predicted, the level of carbon dioxide or its equivalent in other greenhouse gases doubles from pre-Industrial Revolution concentrations, the global average temperature will increase, and that the increase will be 1.5 to 4.5 degrees Celsius or 3 to 8 degrees Fahrenheit... In Dallas, for instance, a doubled level of carbon dioxide and other gases like methane, would increase the number of days a year with temperatures above 100 degrees from 19 to 78 each year.