Brazilian President-elect Luiz Inácio Lula da Silva on Wednesday declared at a U.N. climate conference that “Brazil is back” on the international stage, pledging to a rapturous crowd his intention to build his nation back into a global climate leader after four years of rapid deforestation of the Amazon.

Lula’s appearance at the COP27 climate talks in Egypt was closely followed both by Brazilians and globally by advocates who hope his leadership could prove crucial to international efforts to avoid the worst-case effects of climate change. Because the Amazon rainforest is so vast, its fate is critical to global emissions. And because Brazil is a major developing nation, it has the credibility and heft to pull wavering countries into increasing their climate ambitions, giving it a power that transcends its borders.

A burn area in Brazil last year. Raphael Alves/For The Washington Post

The talks were entering their final days on Wednesday, as nations argued over how much money vulnerable countries were owed for the damage of a warming world. Negotiators were having difficulty agreeing who should pay, and for what, with especially sharp disagreements about the role of China, the world’s biggest emitter, which has fewer climate obligations because it is still classified as a developing country.

It is unusual for a politician who does not yet formally hold office to dive into international negotiations in a format such as the climate talks – Lula takes the reins Jan. 1, and the current president, Jair Bolsonaro, has sent his own emissaries to represent Brazil in an official capacity at the talks. But Lula met with top officials including U.S. climate envoy John Kerry and China’s top climate negotiator, Xie Zhenhua, a sign of the global urgency to engage with a Brazilian leader who, unlike Bolsonaro, does not question basic climate science.

“This is an acknowledgment that the world is in a rush to discuss with Brazil again about the future of the planet and the future of the inhabitants of this planet,” Lula told a packed room of people, some of whom punctuated his speech with cheers, applause and soccer chants that included his name.

“There is no climate security for the world without a protected Amazon. We will spare no effort to bring deforestation and degradation of our biomes to zero by 2030,” he said. “The fight against climate change will have the highest profile in the structure of my government.”

Lula also offered to host a future U.N. climate conference, suggesting it could be held in the Amazon region.

Under Bolsonaro, rates of deforestation in the Amazon reached record highs. Satellite images show the ecosystem has shrunk by about 17 percent, and parts of the forest now emit more carbon dioxide than they absorb. Preliminary data from Brazil’s National Institute for Space Research shows that between January and October 2022, the deforestation rates were the highest since the current monitoring system began in 2015.

That means many advocates depict the election results as a crisis barely averted, even as they acknowledge the scale of the challenges Lula will face as he addresses competing interest groups and a deeply divided society that only narrowly delivered him to office.

“We Brazilians were deciding between having an Amazon or having Bolsonaro,” said Marcio Astrini, the executive secretary of the Brazilian Climate Observatory, a research group. Lula “really understands the weight of these agendas.”

In one first measure of Brazil’s newly open attitude toward international climate cooperation, Brazil, the Democratic Republic of Congo and Indonesia on Monday announced an initiative to try to channel international funding toward forest protection efforts. The plan left many details unresolved, but advocates still said that the fact that Brazil was engaging in international projects was a promising sign for the future, especially as an international leader in fighting deforestation.

“The 60 million Brazilians who voted for Lula may well have voted to save the planet,” said Steve Schwartzman, who oversees tropical forest policy at the Environmental Defense Fund.

Lula was Brazil’s president from 2003 until 2010, a stretch during which Amazon deforestation also decreased even though climate issues were not the dominant focus of his presidency.

But he made global warming and deforestation major issues in this year’s campaign and vowed in his victory speech last month to elevate climate issues during his presidency – which was why he decided to attend the summit even though he is not yet in office.

The decision to go to COP27 created a logistical challenge, and he has received some criticism in Brazil for traveling to Egypt in a private jet owned by a businessman who has been investigated for corruption. Lula’s party acknowledged the political cost but said he could not afford to pay for his own private transportation and that taking a commercial flight was a safety risk.

“Lula is as convinced today about the environmental issue as he has always been about the social issue,” Marina Silva, who was environmental minister under Lula and is his spokeswoman for environmental issues, said in an interview last month.

Global climate policymakers gathered in Egypt welcomed the interest. They said that given the shared sacrifice and compromises that are often needed to advance negotiations, having the productive engagement of a major country like Brazil can make a big difference in pulling others along.

Ghanaian climate envoy Henry Kokofu called it “quite gratifying” to see Lula at the Egypt talks, especially after the country’s relative lack of climate ambition under Bolsonaro.

“Brazil is a big brother when it comes to rainforest goals,” he said.

The importance of the Amazon and the size of the Brazilian economy give the South American country much more clout in negotiations, he said. Rainforest nations including Ghana have been concerned about how previously existing programs that pay for forest preservation will fit into a new carbon market being established under the Paris agreement.

“Brazil is the forest superpower. So they exercise a lot of gravitational pull when it comes to other forest nations,” said Glenn Hurowitz, the chief executive of Mighty Earth, a Washington-based environmental activism group that has fought deforestation in Brazil.

“It’s remarkable to have a head of state of a country as big and important as Brazil making climate as big a priority as he is,” Hurowitz said. “When you combine the United States’ dramatic increase in climate action with the deforestation action Lula has planned, it could make broader international climate action significantly easier.”

Apart from eliminating the use of fossil fuels, scientists say, preserving the Amazon and other tropical forests is one of the most meaningful measures humanity can take against climate change – allowing the world to avoid about 1 degree Celsius of warming. The landscape also plays a critical role in regulating weather patterns; its trees saturate the air with a massive amount of water that ultimately rains down on countries thousands of miles away.

A study published in the journal Nature Climate Change in March showed the Amazon could soon approach a “tipping point,” at which areas of rainforest are replaced by drier, more open spaces. This would release millions of tons of carbon stored in the rainforest’s soils and trees, making it impossible for the world to limit warming to 1.5 degrees Celsius above preindustrial levels.

“President Lula’s return lived up to the immense hope of Brazilian and global society that Brazil is back as a protagonist in the fight against climate change,” said Ana Toni, executive director at the Brazil-based Institute of Climate and Society. “Only together, North and South countries, can we face this challenge, and Lula clearly understood this responsibility.”