LONDON — European leaders have reacted with growing fear and anger to the fires ravaging Brazil’s rain forest, calling it a worldwide crisis that is accelerating global warming — and one that Brazil’s leader appears unwilling to combat.
President Emmanuel Macron of France went so far, on Friday, as to accuse President Jair Bolsonaro of Brazil of lying about being committed to fighting climate change and protecting the Amazon forest.
As a result, Mr. Macron said, he would try to kill a major trade deal between Europe and South America that has been years in the making.
Mr. Macron’s statement was an escalation in a series of sharp comments and accusations he has traded with Mr. Bolsonaro, an unusually harsh exchange between the leaders of two democracies.
The French president and Chancellor Angela Merkel of Germany both said that the Amazon fires should be added to the agenda of the Group of 7 summit meeting being held this weekend, and that Mr. Bolsonaro replied by telling them to keep their noses out of Brazil’s business.
The fires have prompted a widespread backlash against Brazil and its far-right president, who has cut back on protection of wild lands and wants to open more rain forest to farming and ranching.
Environmentalists and celebrities have called for a boycott of the country, and Germany and Norway have halted payments to a $1.2 billion Amazon conservation program after Mr. Bolsonaro’s government interfered with its leadership.
While many of the fires have been set by farmers on lands that were previously cleared, others were set by people clearing rain forest anew, for crops or pastures. The number of fires has increased sharply this year, and environmentalists say Mr. Bolsonaro’s government has enabled and even encouraged the destruction, which it denies.
Mr. Bolsonaro claimed this week that nongovernmental organizations had set fires to make his administration look bad, in retaliation for having their government grants cut, but conceded that he had no evidence for the accusation. He said that his country did not have the resources to fight the fires effectively.
The Amazon forests are an important global repository of carbon, and when trees are burned they release carbon dioxide, the primary greenhouse gas, into the atmosphere. In addition, deforestation threatens indigenous peoples and wildlife found only in that region.
On Thursday, Mr. Macron tweeted: “Our house is burning. Literally. The Amazon rain forest – the lungs which produces 20% of our planet’s oxygen – is on fire. It is an international crisis.”
He said the Group of 7 should take up the matter at its meeting, which begins Saturday in Biarritz, France.
Mr. Bolsonaro accused Mr. Macron of trying to use the issue “for personal political gain.” The idea of major powers discussing a Brazilian problem without including Brazil, which is not a Group of 7 member, “evokes a misplaced colonialist mind-set,” he wrote.
But it soon became evident that Mr. Macron was not alone. The United Nations secretary general, António Guterres, said, “in the midst of the global climate crisis, we cannot afford more damage to a major source of oxygen and biodiversity.”
On Friday, Steffen Seibert, a spokesman for Ms. Merkel, said at a news media briefing that “the extent of the fires in the Amazon area is shocking and threatening, not only for Brazil and the other affected countries, but also for the whole world.”
Like Mr. Macron, he said, “the chancellor is convinced that this acute emergency” should be on the Group of 7 agenda.
A spokesperson for the European Commission called the fires in Brazil “deeply worrying,” adding that “greenhouse gas emissions linked to deforestation are the second-biggest cause of climate change, so protecting forests is a significant part of our responsibility to meet the commitments under the Paris Agreement.”
Mr. Macron raised the stakes on Friday by taking a stand against one of the biggest trade agreements in history, between the European Union and Mercosur, the trading region that includes Brazil, Argentina, Paraguay and Uruguay. The deal, struck in June after two decades of negotiations, would lift tariffs on about $1 trillion worth of annual trade.
The agreement has met stiff opposition from environmental groups that say it would encourage the destruction of forests to make way for agriculture, and from farmers who fear cheap South American imports.
Mr. Macron, an advocate of battling climate change and a leader of one of the world’s biggest agricultural producers, has been hesitant about the deal. In June, before a political agreement was reached on the deal, he threatened to block it if Mr. Bolsonaro pulled Brazil out of the Paris climate accord, as he had threatened to do.
“We’re asking our farmers to stop using pesticides, we’re asking our companies to produce less carbon — that has a competitiveness cost,” Mr. Macron said at the time. “So we’re not going to say from one day to the next that we’ll let in goods from countries that don’t respect any of that.”
The two presidents discussed the matter later that month, at a Group of 20 meeting in Osaka, Japan.
“Given Brazil’s attitude over the past weeks, the president of the republic can only conclude that President Bolsonaro lied to him at the Osaka summit,” Mr. Macron’s office said in a statement released on Friday morning.
“Brazil’s decisions and comments over the past weeks show that President Bolsonaro has decided not to respect his obligations on climate change, nor to commit on issues related to biodiversity. Under these conditions, France is opposed to the Mercosur agreement as it stands.”
To go into effect, the agreement must be ratified by the European Parliament, and some member nations might insist on having their national parliaments vote on it, as well. Resistance to it was already strong enough that Mr. Macron’s opposition could be decisive.