The latest computer modeling I've seen indicates that at mid-century, there might be 150 million people classified as "environmental refugees."

On the top of these mile thick slabs of ice the water is percolating quickly to the base and greasing the skids, as it were, for the slide of that ice into the ocean.

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.

We'll look for almost any reason not to change our attitudes; the inertia of the established order is powerful. If we can think of a plausible, or even implausible, reason to discount environmental warnings, we will.

The Arctic and the Antarctic are melting quickly. We may have waited too long to get started. But this is a day for optimism because the battle is fully joined, and the idea that big oil is unbeatable is no longer true.

All the science in the last few years, or almost all of it, really serves to show that the [climate] effects are larger and more rapid than we had thought even a decade ago.

Very few people on earth ever get to say: 'I am doing, right now, the most important thing I could possibly be doing.' If you'll join this fight that's what you'll get to say