We are running out of time, we must have a planetary solution to a planetary crisis.

I flew on Air Force Two for eight years, and now I have to take off my shoes to get on an aeroplane.

Our world faces a true planetary emergency. I know the phrase sounds shrill, and I know it's a challenge to the moral imagination.

The entire North Polar ice cap is disappearing before our very eyes. It's been the size of the continental United States for the last 3 million years and now 40 percent is gone and the rest of it is going.

The mountain glaciers in every region of the world are melting, many of them at an accelerated rate, threatening drinking supplies - drinking water supplies and agricultural water supplies. We have these record storms, drought, floods, fires, three deaths (ph) in the American West, climate refugees beginning now, expected to rise to the hundreds of millions unless we take action.

There are many who would much prefer that the word 'climate' never be mentioned and that the issue be eliminated from our national conversation.

We have to abandon the conceit that isolated personal actions are going to solve this crisis. Our policies have to shift.