We ought to approach this challenge [of global warming] with a sense of profound joy and gratitude: that we are the generation about which, a thousand years from now, philharmonic orchestras and poets and singers will celebrate by saying, they were the ones that found it within themselves to solve this crisis and lay the basis for a bright and optimistic human future.

Anyone who deals with the climate crisis has an internal dialogue between hope and despair, because the challenge is so huge and the danger is so great and the stakes are so high. But I have always resolved that in favour of hope, and actually I'm more hopeful now than I was a decade ago when the solutions were visible on the horizon, but you had to seek reassurance that the technology experts that they're coming, they'll be here.

There's no such thing as clean coal. It's non-existent. Theoretically, it might be possible, many years from now, to come up with a way to clean it as it's burnt. But there's not a single demonstration project in the United States. [...] Clean coal doesn't exist.

The cost reductions for renewable energy continue downward in a very dramatic way. We're in the early stages of a sustainability revolution in the globe that has the scale of the industrial revolution but the speed of the digital revolution. And you see it with renewable energy and you see it with LED lighting, which takes a fraction of the energy for the existing bulbs. All new lights are going to be LED. Electric vehicles. There are a lot of changes underway right now. I'm excited by the prospect, and I look forward to working in the months and years to come to accelerate this transition.

I saw the logarithmic growth of computer power.

The warnings about global warming have been extremely clear for a long time. We are facing a global climate crisis. It is deepening. We are entering a period of consequences.

The Himalayan Glaciers on the Tibetan Plateau have been among the most affected by global warming. The Himalayas...provide more than half of the drinking water for 40% of the world's population...Within the next half-century, that 40% of the world's people may well face a very serious drinking water shortage, unless the world acts boldly and quickly to mitigate global warming.