John Kerry: “The president needs to step up and acknowledge that there are difficulties and that the world needs to be involved.”

The reason that happened, my friend, is because Donald Trump pulled out of that agreement.

No, that's not acceptable. And I believe it was an algorithm that kicked that out kind of crazily.

It's a matter of mathematics and physics, not politics, not ideology. It is a response to the science.

you cannot just sit there anywhere and wish that things are going to be as they have been historically.