The Amazon is burning. Brazil’s president accused critics of setting fires to make him look bad.

RIO DE JANEIRO - The signs of crisis are everywhere.

Sao Paulo, the Western Hemisphere's biggest city, was covered in a blanket of smoke this week that turned night to day. The viral campaign #PrayfortheAmazon is washing across social media. And one of the government's leading research agencies is saying that rates of deforestation in the Amazon are skyrocketing - along with the rate of forest fires.

But Brazilian President Jair Bolsonaro, the man most able to staunch the unfolding crisis in the Amazon, isn't just ignoring the problem. He's suggesting it's being staged to make him look bad.

Asked this week about the surging fires in the world's most precious forest - the area scorched has more than doubled in the past two years - he accused nongovernment organizations of setting them, to "call attention" against his government.

"The fire was started, it seemed, in strategic locations," he said. "There are images of the entire Amazon. How can that be? Everything indicates that people went there to film and then to set fires. That is my feeling."

This comes weeks after he accused the director of a government agency that monitors the Amazon of lying about rising deforestation - and fired him. He's also embroiled in a public spat with Germany and Norway, who have cut aid to the Amazon over his policies.

The controversies have become not only a major political distraction, drawing criticism from some of the nation's most prominent scientists. They're also posing a mortal threat to Brazil's position as global leader on the environment.

Climate change "is a theme of the global agenda," said Mauricio Santoro, a professor of international relations at the state university in Rio. "And Brazil plays a central role, whether it wants to or not, because of the Amazon, because of its biodiversity."

And because of what's happening there.

Bolsonaro ran for office last year in part on promises to open the Amazon for business. Deforestation has surged since he took office at the beginning of the year. In July alone, according to Brazil's National Institute for Space Research, the Amazon lost 870 square miles of forest - more than half the size of Rhode Island.

Destruction and human contact inside the forest is making what was once thought to be all but impossible - wildfires in a rainforest - possible. The area in Brazil’s Amazon regions razed by fire has more than doubled in two years, from 3,168 square miles during the first seven months of 2017 to 7,192 square milesduring the same period this year, the space institute reported.

The Amazon forest serves as the lungs of the planet, taking in carbon dioxide, storing it in soils and producing oxygen. Scientists agree that it is one of the world's great defenses against climate change.

In Brazil, the Amazon has suffered 74,155 fires since January, the space research institute reported. That's up 85 percent from last year and significantly higher than the 67,790 blazes at this point in 2016, when there were severe drought conditions in the region associated with a strong El Niño event.

Farmers and others burn the rainforest to clear land and maintain open space. Bolsonaro, trying to lift the country out of years of economic stagnation, is encouraging development in the region.

But Carlos Nobre, one of Brazil's foremost scientists, says that activity will cause still more harm.

"We make a joke that the forest is becoming like Swiss cheese, with . . . roads and things crossing in the forest," he said. "And it becomes more vulnerable and degraded. . . . And the more the forest becomes degraded, the more the forest will become vulnerable to forest fires."

Those fires, fueled by winds from an incoming cold front, produced scenes this week that were both startling and ominous: Smoke darkening the midday skies over Sao Paulo and other cities. Day became night, leading to diffuse confusion - and a lot of jokes.

"Apocalypse!" one person cried on Twitter.

"The final judgment is coming!" another added.

"Mordor!" one person said.

The humor belied a grim reality: Hundreds of miles away, the Amazon was burning.

"It is disturbing that forest fires have been in evidence in a year that is not one of extreme drought," said Philip Fearnside, an ecologist at the National Institute for Research in Amazonia.

Forest fires are common in Brazil - but not at this rate, said Vitor Gomes, an environmental scientist at the Federal University of Para.

"I cannot remember any other big fire episode like this one," he said. "It is also sharply overlapped with the increased deforestation. Attributing the whole episode to natural causes only is practically impossible."

The contrast between Bolsonaro's claims and what the science says has researchers worried over how to safeguard one of the world's most important resources. Scientists warn that the Amazon is approaching a tipping point, at which the damage done to the forest could become irreversible.

"Anyone can go to [the space research institute] and see the fire alerts all over," said Ricardo Mello, head of the World Wide Fund for Nature's Amazon Program. "You can see that they're real - they're seen by infrared cameras. There's no way that you can deny this. . . . It's very naive for him to say that's not happening."

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The Washington Post’s Marina Lopes in Sao Paulo and Andrew Freedman in Washington contributed to this report.