ROME — U.S. climate czar John Kerry met with Pope Francis in the Vatican this weekend in preparation for the upcoming U.N. climate conference in Glasgow.

The pope “is one of the great voices of reason and compelling moral authority on the subject of the climate crisis,” Kerry told Vatican News. “He’s been ahead of the curve. He’s been a leader. His encyclical Laudato Si is really a very, very powerful document, eloquent and morally very persuasive.”

Francis will be “a very important voice leading up to and through the Glasgow conference, which I believe he intends to attend,” said Kerry, who serves as Special U.S. Presidential Envoy for Climate. “So, we need everybody in this fight. All the leaders of the world need to come together and every country needs to do its part.”

His Holiness “speaks with a moral authority that is quite separate,” Kerry added. “It’s unique and we need all the power we can bring to the table.”

Kerry is currently traveling in Europe to meet with European government officials and business leaders in Rome, London, and Berlin in preparation for the 26th Conference of the Parties (COP26) to the U.N. Framework Convention on Climate Change, scheduled to take place next November.

Last January, Kerry told the BBC that humanity has only nine years to save the planet from man-made climate change.

“Glasgow will be extremely important,” Kerry said. “In fact, I would say that in my judgment, it is the last best chance the world has to come together in order to do the things we need to do to avoid the worst consequences of the climate crisis.”

“Three years ago, we were told we have 12 years to avoid those consequences,” Kerry added. “Three of those years were lost because we had Donald Trump, who didn’t believe in any of it. And now we have nine years left to try to do what science is telling us we need to do.”

The following month, however, Kerry came under fire when it was revealed he had taken a private jet to Iceland in 2019 to accept the Arctic Circle Prize for his leadership on climate change. Private jets are estimated to generate some ten times the amount of green house gas emissions per passenger as compared to commercial air travel.

Kerry defended his choice of transportation, saying that a private jet was “the only choice for somebody like me who is traveling the world to win this battle.”

“No country is exempt from needing to take measures to deal with this crisis,” Kerry told Vatican News this weekend. “On the other hand, we don’t expect a very small economy, a very small country, and a very small emitter of greenhouse gases to step up and do the same thing we’re going to do.”

The United States “has to put up its fair share of funding for adaptation for resilience,” he said. “We have to lead in helping to cut our emissions — and we are!”

“If the United States was at zero-emissions tomorrow, we’d still have crisis,” Kerry asserted. “We are only 11 percent of all the world’s emissions. So, 89 percent is other countries. Twenty countries are responsible for about 73, 75 percent of the emissions.”

“And I think His Holiness, the Pope Francis speaks with unique authority, compelling moral authority, and that hopefully can help push people to greater ambition to get the job done,” Kerry added.

“The Holy Father is one of, if not the, one of the most powerful voices on the planet and he’s been extraordinary in the eloquence of his call on people to do to step up and be reasonable and to live out our responsibility as human beings in caring for God’s creation,” Kerry said.

The pope is “above politics,” Kerry added, and so “he can sort of shake people a little bit and bring them to the table with a better sense of our common obligation.”

“So, I think that the world has a special respect for Pope Francis and there is no question that he has already been a significant leader in this endeavor,” he said. “And we look to him for further guidance and help in getting this job done.”