If Donald Trump were elected president, he would be the only world leader who does not believe in climate change—or even in calling for action on global warming.

That's what the Sierra Club found in a comprehensive analysis of verifiable quotes, statements, and actions from global heads of state, released Tuesday, which also warns that the presumptive Republican nominee's steadfast denial of climate science could threaten relationships between the U.S. and its allies.

"Donald Trump's failure to acknowledge basic climate science wouldn't just leave him isolated on the world stage as President, it would undermine our relationships with key allies and threaten our ability to work effectively internationally. Trump's climate science denial would make him a global laughingstock if it wasn't so dangerous," said Sierra Club global climate policy director John Coequyt. "Every single leader on earth—from Germany to India to Somalia to Japan—recognizes that the climate crisis is happening and demands the world's attention, but Trump is sticking his head in the sand while the seas are rising."

The report, On the Climate Crisis, It's Donald Trump vs. the World (pdf), compiles official statements from 195 independent nations worldwide that recognize the dangers of global warming and the need to curb rising greenhouse gases, and compares them to the various ways in which Trump has dismissed, denied, and ridiculed the very concept.

"It is important that we act, because climate change is becoming an increasingly serious problem for all nations," Japanese Prime Minister Shinzo Abe said last year.

In comparison, Trump tweeted in 2014, "Is our country still spending money on the GLOBAL WARMING HOAX?"

The U.S. and more than 170 other nations signed the Paris accord in April, committing to keeping global temperature rise to under 2°C.

Canadian Prime Minister Justin Trudeau said at the time, "Climate change will test our intelligence, our compassion and our will. But we are equal to that challenge. I encourage other signatories to move swiftly to follow through on their commitments."

A month earlier, Trump attacked "draconian climate rules" in an energy policy speech and said that as president he would "cancel the Paris climate agreement and stop all payments of U.S. tax dollars to UN global warming programs."

The list, the Sierra Club reports, goes on.

Bolivian President Evo Morales said of the Paris agreement, "The response to global warming is global democracy for life and for the Mother Earth. Let us choose to be clean and active today for the sake all of humanity, not toxic and reactive tomorrow, against nature."

German Chancellor Angela Merkel said, "Ladies and gentlemen, ambitious, comprehensive, fair, and binding—a global climate agreement should and indeed must be all those things. This is a question of both ecological necessity and economic common sense. It is a question of intergenerational equity. It is a question of our humanity, and on it depends the future of the human race."

Marshall Islands President Hilda Heine: "No President wants one of their first acts in office to be to declare a state of disaster. But by becoming one of the first countries to ratify the Paris Agreement, we have shown our determination to continue to lead this fight from the front."

And then there's Trump. "Let's continue to destroy the competitiveness of our factories & manufacturing so we can fight mythical global warming," he tweeted in 2012. "We can't destroy the competitiveness of our factories in order to prepare for nonexistent global warming."

"We should be focusing on beautiful, clean air & not on wasteful & very expensive GLOBAL WARMING bullshit!" he wrote again in 2013.

UN Secretary-General Ban Ki-moon said that the Paris agreement signing marked "a moment in history. Today you are signing a new covenant with the future."

One that a Trump presidency would all but guarantee to ruin, Sierra Club said.

"Anybody who cares about the health of our communities and the safety of our planet needs to know that Donald Trump would be the only leader of any nation determined to let it burn, if elected," the group's political director Khalid Pitts concluded.