We face a climate crisis now that is the most serious challenge our civilization has ever confronted. And the greatest country in the world [America] has to remain a part of this unprecedented global agreement to deal with it.

As president, I will bring all the parties and stakeholders together. I am going to come up with a solution that respects the environment and does not cause an upheaval in the economy.

There are good people, who are in politics - in both parties - who hold this at arm's length, because if they acknowledge it and recognize it, then the moral imperative to make big changes is inescapable.

One tragic example of the loss of forests and then water is found in Ethiopia. The amount of its forested land has decreased from 40 to 1 percent in the last four decades. Concurrently, the amount of rainfall has declined to the point where the country is rapidly becoming a wasteland.

The climate crisis is not a political issue; it is a moral and spiritual challenge to all of humanity. It is also our greatest opportunity to lift global consciousness to a higher level.

The catastrophe now threatening us is unprecedented - and we often confuse the unprecedented with the improbable.

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