Thirteen months later, it has all been undone — by President Trump’s decision to withdraw from the historic Paris climate agreement.

It was Earth Day, 2016, and for Kerry it marked the culmination of not only years of diplomacy but a lifetime of work. As he reflected that day on the accomplishment, he quoted a simple phrase from Nelson Mandela: “It always seems impossible until it is done.”

WASHINGTON — John Kerry sat in front of the United Nations, his 2-year-old granddaughter, Isabelle, in his lap as he affixed his signature to a historic climate accord. He smiled. He gave Isabelle a peck on the cheek. He blew a kiss into the crowd.


“It was a day of craven ignorance and cynicism that moved the presidency of the United States away from global leadership into a narrow little niche of ideological, political self-preservation,’’ Kerry said in an interview with the Globe on Friday. “It’s tragic for the consequences. It’s also built on an enormous lie that the economy is somehow hurt by the steps that were being taken.”

“I think it will be recorded as one of the most self-destructive days in presidencies ever,” he added.

As Kerry watched Trump’s announcement Thursday, he grew angrier — on a personal front, for his grandchildren; on a political front, for what he sees as the reduction of America’s role in the world; on a scientific front, for what would happen to the earth.

Kerry argues that the pieces for a transformation of energy production are moving into place. The solar power and wind turbine sectors are booming, he said. At least 2.6 million clean-energy jobs have been created, he added, half of which are in states carried by Trump.

“Trump tried to make a fake economic argument. He delved into fake news throughout his comments. They don’t stand up to scrutiny at all,” Kerry said. “He’s tried to make the argument that somehow the forgotten man in America is getting screwed by this agreement. But the truth is the forgotten man in America is getting screwed by Donald Trump and his choices. And slowly that truth is going to sink into people when they see what happens.”


Kerry would not get into details, but he says he has heard lately from a number of world leaders about Trump’s behavior on the international stage.

“They’re shocked. They’re scratching their heads,” he said. “For one thing, he’s been rude to people. He’s been rude to people on his trip. He pushes people out of the way. He’s rude in his conversations. He wouldn’t take phone calls from certain leaders. . . . He’s burning bridges, not building them.”

Deputy White House press secretary Sarah Huckabee Sanders rebutted Kerry, saying he was failing to grasp the concerns that the electorate made clear in November.

“With all due respect Secretary Kerry sounds unhinged and his comments here reflect just how out of touch he and his party are with everyday, hard-working Americans,” she said. “This constant misunderstanding of what the American people want is exactly why Donald Trump is the president and Hillary [Clinton] isn’t.”

Kerry played an instrumental role in crafting the Paris climate accord, in which 195 countries agreed to combat climate change by cutting greenhouse gas emissions. It was one of the signature accomplishments during Kerry’s four years as secretary of state, along with a deal with Iran that Trump has also ridiculed.


“It’s deeply frustrating having come off four very serious years that dealt with real issues and looked for real solutions to see the presidency reduced to such basic sloganeering and cynical politics,” Kerry said. “It doesn’t fit the times. And I find that very — it’s frustrating but it’s energizing. I mean, I get motivated. I’m going to go out and do what I have to do to change that.”

When Kerry left the State Department as Trump was inaugurated, he concluded nearly 34 years in public office. He had always expected that his post-government role would involve some amount of continuing to argue for action on climate change — and preserving the Paris agreement — but the degree to which he’s now engaged seemed to surprise even him.

“This is not what I expected or wanted to be doing but I’m going to be doing this to a fare-thee-well now in order to push back against the nihilism and cynicism that’s driving the choices of this administration,” he said. “Donald Trump pulled out of that agreement — not the American people.”

“The consequences of the choices he is making affect my children and my grandchildren in a very personal way. That’s a motivator beyond description,” he added.

Combating climate change has been one of the issues that has most animated Kerry throughout his career.

He was a member of a US delegation at Rio de Janeiro in 1992, the first major meeting on international climate change, and he has been to most global conferences on the topic since. He met his future wife, Teresa, at an Earth Day rally and in 2007 they wrote a book together called “This Moment on Earth: Today’s New Environmentalists and Their Vision for the Future.”


In 2009, he crafted the Senate’s most ambitious response to threats of climate change, legislation that would have established a cap-and-trade system on US emissions of greenhouse gases.

The legislation failed, which Kerry said was one of the biggest regrets of his Senate career.

Kerry was flying to Antarctica to view some of the impacts and research related to climate change when he learned that Trump had defeated Clinton.

“Those of us who started with Earth Day in 1970 in response to Rachel Carson have a really powerful sense of the stupidity and self-destructiveness and ignorance of the decision that has been made,” Kerry said.

“Who’s asking for this stuff? Not the average American,’’ he said. “They don’t want coal in their water, they don’t want methane coming out of their faucets. And Trump is fooling with this stuff, he’s playing with it. It’s very, very dangerous.”

“This is driven by [Steve] Bannon and [Scott] Pruitt — by extremists,” he said, referring to the White House senior adviser and head of the EPA. “You know, America is not extremist. But those guys have put their nonscientific climate denial views on the line and Trump has bought it hook, line, and sinker. And he’s using it to try to galvanize his base at a time when he’s going to be under assault with hearings and investigations.”


In the interview Friday, Kerry — who lost a 2004 presidential race, who led Vietnam War protests, who spent decades in the Senate — began to contemplate this political era.

“This is a very unique moment in American politics and a very dangerous moment,” he said. “It’s not just another political move, it’s not just another fight in Washington, it’s not just another day. That is a big confrontation and a big choice.”

“This is not a short-term game, this is not something you play with. This is serious business,” he added. “This is going to affect conflicts, this is going to affect wars. This is going to affect lives. Refugees. Livelihoods. This has profound impact, what he has done.’’

“You can’t sit on the sidelines as a citizen,’’ he added. “You don’t have that right.”

Kerry reflected on his quote from Mandela last year, about work seeming impossible until it is done.

“The work does still continue,” Kerry said. “You know? Teddy Kennedy reminded us of that in his famous speech: ‘The cause endures, the fight goes on.’ And it does. In life, nobody said it is going to be easy. We all know, it’s a continuing fight. So we step up and we go to war.”

Matt Viser can be reached at matt.viser@globe.com.