• U.S. climate envoy Secretary John Kerry called out President Donald Trump's lack of climate action in his term in the White House on Tuesday, but said the U.S. can regain the world's trust through action.
• He also said that scientists fear we're reaching irreversible tipping points on ice melt, coral reef destruction, and other areas: 'That should scare the hell out of folks," Kerry said.
• He acknowledged the private sector is coming together in the fight, and said countries must step up as well.

U.S. climate envoy John Kerry called out President Donald Trump's lack of climate action in his term in the White House on Tuesday. Kerry also warned that damage being caused by climate change is in some cases irreversible.

"I refuse to accept the idea that the sheer idiocy and lack of scientific rationale and legitimate economic rationale or even political rationale for Donald Trump pulling out — I refuse to believe that creates something that's irreparable for people of good faith in good conscience who want to do what's right," Kerry said, speaking at an event for Climate Week NYC.

Trump removed the United States from the Paris Climate Accord, an action that Biden reversed earlier this year. Kerry said that the U.S. will only be able to regain the world's trust through action.

"My goal is not specifically to restore trust. That's a byproduct of what we're doing," Kerry said. "It gets restored by acting, it gets restored by being out there doing the things that are necessary to to address the issue, the fundamentals of the issue."

"Let the chips fall where they may as to people's judgement about what the United States is doing," Kerry said.

Indeed, as Kerry admonished the previous administration's lack of action, he also warned that the Biden administration has an unmitigated crisis on its hands.

"Mother Nature's sending the clearest signals ever about the rapidity with which the evidence is accelerating, about the dire circumstances that are developing," Kerry said.

California and the western U.S. have been hit by multiple large fires this season, record heat waves and a "heat dome," and deadly flash floods in the Northeast.

Across the board, countries are not changing fast enough to respond to and mitigate climate change.

"We have the latest IPCC report, which stresses that we've got to deploy renewables far faster, six times faster than we then we are today, we've got to begin reducing our dependency on the dirtiest fuel in the world, coal. And we have to do that five times faster than we're doing today," Kerry said. "We have to do reforestation five times faster. we have to make the transition to electric vehicles happen about 22 times faster. So we are behind. And that's the bottom line."

He also warned about passing climate tipping points where certain damage cannot be reversed.

"Scientists will tell you that not only do they fear that we may have reached tipping points on the Arctic and the Antarctic and on coral reefs, but they see many of the changes that are taking place, if not all of them, as irreversible — that should scare the hell out of folks."

Kerry has seen positive response from company leaders, he said.

"There's also an interesting thing happening, which I find may be the thing that actually makes the greatest difference of all that is, the private sector around the world is really moving," he said. "And CEOs have come to understand that this affects their lives, affects their personal lives affects their countries, it affects their ability to do business around the world without disruption without terrible consequences."

But even as companies are getting more serious, Kerry said the climate crisis will not be addressed without countries coming together.

"We're not going to get it done alone, that's for sure. No one nation can get this done. This gets done by the best of diplomacy and the best of international engagement coming together," Kerry said.

Fundamentally, Kerry said it's key to remain hopeful, engaged and moving forward productively.

"The most important thing: We can make the difference. This is doable. It's not a lack of capacity, it's a lack of political will."