For decades the battle to protect the Amazon has been fought inside the rainforest, with armed enforcement officers squaring off against illegal loggers, gold miners and land grabbers. But the latest flashpoint in Brazil’s environmental tussle is over the data used by scientists to highlight the extent of the devastation.

Since Jair Bolsonaro came to power, scientists monitoring the destruction of the Amazon — typically using satellite imagery — have faced pressure from his rightwing government, which has poured scorn on their findings.

The populist president has questioned the reliability of monthly data from the National Institute for Space Research, or INPE, that showed a surge in deforestation, saying it did “not match reality”. He later fired the institute’s director.

“We have reached a state where baseless accusations have become acceptable common practice,” Gilberto Camara, a former director of the INPE, said last month, as he accused the government of trying to undermine science.

In recent months the row has gained an international dimension as Norway — which has long been a keen observer of events in the Amazon — has started to publish its own satellite imagery, which it says will limit the room for disputes over deforestation.

The dispute and the government’s questioning of scientists’ data on deforestation has far-reaching consequences for Brazil and the rest of the world.

The Amazon’s destruction is approaching what scientists believe to be a “tipping point”, where the rainforest’s complex ecosystem will be unable to support itself, leading to the rapid death of forest and severe climate fluctuations across the world. For scientists, accurate monitoring of these developments is crucial.

“We would have no control without monitoring. We wouldn’t be able to deploy task forces to stop deforestation. The images are also crucial for Brazil to meet its international commitments on carbon emissions,” said Claudio Almeida, of the INPE.

Nina Soleng, from Kongsberg Satellite Services, an imagery and data provider working with the Norwegian government, said it was important to support the need for transparency.

“When everyone sees the same, there can be no question about the facts, but rather questions about what can we do about it — how can we stop deforestation and climate change and conserve biodiversity,” she said.

Brazil’s vice-president Hamilton Mourão, a former army general, has fuelled the dispute with the INPE in recent comments, accusing the institute of political motivation.

“There is someone inside INPE that opposes the government. When the data is negative for us, [INPE] discloses it. When it is positive, it does not disclose anything,” said Mr Mourão, the head of Brazil’s Amazon Council.

Mr Camara, the former INPE director, said the vice-president “only understood tanks and not satellites”. He added: “The INPE’s soul is science. Its work is done by people who believe in the value of science and they are more difficult to intimidate.”

The vice-president later had a change of heart and praised the INPE for its “extraordinary work”.

The Norwegian move is part of a broader push by European nations and companies to put pressure on Brazil over the destruction of the Amazon, where deforestation between August last year and July this year reached a 12-year high of 11,000 square kilometres.

The Brazilian president is also likely to face increasing pressure from the US administration of president-elect Joe Biden, who highlighted the destruction of the Amazon in a TV debate before he was elected.

Mr Biden said he would support the creation of a multibillion dollar fund to protect the rainforest, but threatened economic sanctions if Mr Bolsonaro did not reply. Mr Bolsonaro responded with typical bluster, threatening the use of “gunpowder” against the US, in comments that were widely mocked.

Global financial groups are also increasingly preoccupied with Brazil’s environmental standards and are making decisions to invest — or divest — based on deforestation data.

In June investors from more than two dozen financial institutions around the world warned that deforestation had created “widespread uncertainty about the conditions for investing in or providing financial services to Brazil”. Many investment groups say they are now facing pressure to divest.

The campaign spurred the Brazilian government to adopt a more proactive stance on enforcing environmental rules and communicating with the rest of the world, although in December Mr Bolsonaro attempted to change the narrative by blaming European nations for buying illegal wood from the Amazon.

Carlos Souza Junior, a researcher at Imazon, an NGO that also uses satellites, said monitoring was a crucial preventive tool as “you are able to look ahead and see where you have the most susceptible areas for deforestation”.

But he added that the monitoring efforts must be matched by enforcement on the ground: “What do we want to do with the data? There has to be a complementary strategy. We have to punish the illegal deforestation.”