Other thing we need to understand is that the financial power of the fossil fuel industry has so far prevented even any minor progress. They have a sweetheart deal unlike any other business on Earth: they're allowed to dispose of their waste for free, to use the atmosphere as an open sewer. And they will do all they can to defend that special privilege.

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

We spend a lot of time playing defence against bad things. So, in the US, one of the focusses has been this huge Keystone Pipeline project, another has been the coal ports on the Pacific Ocean.

We've been given a warning by science, and a wake-up call by nature; it is up to us now to heed them.

In the end, climate change is a math problem.

After a lifetime of nature shows and magazine photos, we arrive at the woods conditioned to expect splendor - surprised when the parking lot does not contain a snarl of animals attractively mating and killing each other.

The fact that Washington has been a complete logjam for anything for the last six years has got to change because we need to have federal policy that really allows us to move quickly and nimbly.