RIO DE JANEIRO — Ricardo Galvão was sure of the data. As director of a Brazilian government agency that monitors the Amazon, he watched as the numbers showed surging rates of deforestation following the inauguration of President Jair Bolsonaro, who has promised to open up the country’s natural reserves to business.

So he was surprised — then furious — when he heard that Bolsonaro, a former military officer known for incendiary comments, wasn’t just doubting the agency’s scientific research. He was dismissing it as “lies.”

The MIT-trained physicist pushed back hard, criticizing Bolsonaro’s “vile, cowardly attitude.”

He was fired on Friday. But he hasn’t stopped talking.

“This was a defense of the dignity of the Brazilian science, not only for Brazilian scientists, but for all scientists,” Galvão told The Washington Post this week. “Our data should never be curbed by political interests.”

The termination of one of the nation’s most respected scientists has alarmed researchers, many of whom say they see his dismissal as an effort by the Bolsonaro administration to clamp down on research it doesn’t want publicized.

“There should be no control by the federal government on the freedom of speech of scientists to say what their science is compelling them to say,” said Carlos Nobre, who has spent decades monitoring deforestation in the Amazon. “The government is saying this is a top-down approach and that you’re not allowed to say this, and you can’t say that. It’s like ‘1984,’ George Orwell and Big Brother.”

The firing of Galvão — he has been replaced by a military official — comes at a precarious time for the world’s largest rainforest. Widespread destruction is quickly pushing the Amazon toward what researchers describe as a tipping point — between 20 and 25 percent deforestation — when they say its climate will change and large swaths will transform into grassy, largely treeless savanna.

Analyses have suggested that the losses over recent months have been devastating: The Amazon is shedding roughly two football fields of forest every minute.

That’s become a political irritant for Bolsonaro. European leaders have repeatedly questioned his stewardship of one of the world’s most precious resources, adding a sour note to recent trade negotiations. He has told them they don’t know what they’re talking about.

“You have to understand that the Amazon is Brazil’s, not yours,” Bolsonaro told a European reporter at a lunch last month with foreign journalists. “If all this devastation you accuse us of doing was done in the past, the Amazon would have stopped existing; it would be a big desert.”

One point of contention has been the findings of the government’s own monitoring agency. Bolsonaro claimed, without offering proof, that the National Institute for Space Research, or INPE, was working “at the service of some NGO.”

“I am convinced the data is a lie,” he said. “We are going to call the president of INPE here to talk about this, and that’s the end of that issue.”

The accusations hit the research agency like a bomb.

“It was insulting,” Galvão said. “And more than that, it was a charge of criminal doing. Saying that this research is a lie is a very serious charge, and we cannot take that and stay quiet. I pray that he’ll never do that again.”

Bolsonaro’s press office didn’t respond to a request for comment on Tuesday.

The accusations of fraud were even more galling, Galvão said, because his agency had been instrumental in one of the world’s great environmental success stories. Using satellite images, it provided rapid warnings to authorities of deforestation, enabling immediate action. Between 2004 and 2012, the rate of deforestation was brought to record lows.

Galvão, who was appointed three years ago by then-President Michel Temer, said he started worrying about the agency’s future during last year’s presidential campaign. Bolsonaro, then a fringe member of Brazil’s congress, campaigned in part on dismantling environmental protections to pave the way for development in the Amazon.

Galvão’s concerns mounted when the Bolsonaro administration took over and started complaining about the accuracy of the agency’s research.

“It was a simple, childish excuse for them not doing what had to be done,” Galvão said. He pointed to reports showing the government hasn’t been as aggressive as it once was in pursuing enforcement action to combat deforestation.

He said he reached out several times to the Ministry of Science and Technologies, warning that rising rates of deforestation “would have very serious consequences for Brazil.”

He said the ministry never responded to those concerns but continued to question the accuracy of the agency’s data.

The Ministry of Science and Technologies didn’t respond to requests for comment.

Rather than speak with him, Galvão said, Bolsonaro instead publicly accused his agency of lying.

“He said we were under the rug of an NGO, and that really annoyed me,” he said. “I said if he’s sure of that, he can look me in the eyes and say that.”

Scientists here worry that Galvão’s firing is only one part of a larger threat to the country’s research institutions.

“President Bolsonaro’s claims that anthropogenic global warming does not exist or that INPE’s deforestation data are false have not been publicly contested at the ministerial level,” said Philip Fearnside, an ecologist at the National Institute for Research in Amazonia.

“It would be a great tragedy if this were to extend to the country’s research institutions.”

Galvão expressed confidence that the agency will continue to accurately describe the status of the Amazon without him.

“They’ll keep providing the right data,” he said. “Even if the government doesn’t want to see it.”

On Tuesday, even as Bolsonaro renewed his attacks on the agency’s “imprecise data,” it released more. The Amazon, it found, had lost 870 square miles of forest — more than half the size of Rhode Island — in July alone.