We do not know how much our climate could or will change in the future. We do not know how fast change will occur or even how some of our actions could impact it.
There's one issue that will define the contours of this century more dramatically than any other, and that is the urgent and growing threat of a changing climate.
The biggest threat, when it comes to climate change and pollution, isn't going to come from us because we only have 300 million people. It's going to come from China with over 1 billion people and India with over 1 billion people.
There are folks who will equivocate. They'll say, 'You know, I'm not a scientist.' Well, I'm not either. But the best scientists in the world know that climate change is happening.
The world must come together to confront climate change. There is little scientific dispute that if we do nothing, we will face more drought, famine and mass displacement that will fuel more conflict for decades.
And yes, my plan will continue to reduce the carbon pollution that is heating our planet - because climate change is not a hoax. More droughts and floods and wildfires are not a joke. They're a threat to our children's future. And in this election, you can do something about it.