The Brazilian Amazon is burning — and the world is taking notice.

So far this year, more than 76,000 wildfires have burned in Brazil — the majority in the Amazon — amounting to an increase of more than 80% over the same time period last year, according to the country’s National Institute for Space Research (INPE).

Brazil contains about 60% of the Amazon, the world’s largest rainforest. Several million plant, animal and insect species live in the Amazon, and it acts as a huge carbon sink that helps to cool global temperatures.

The wildfire data, which INPE released on 20 August, have prompted an international outcry. On 22 August, French President Emmanuel Macron, who is hosting a G7 summit in Biarritz from 24-26 August, called for discussion of the fires at the summit. “It is an international crisis. Members of the G7 summit, let’s discuss this emergency,” he tweeted .

Threatened habitats

An increase in people illegally clearing land for agricultural activities and a decrease in the enforcement of environmental laws are the reason for the surge in fires in the Amazon, says José Antonio Marengo, a climatologist at the National Centre for Monitoring and Early Warning of Natural Disasters in São Paulo. “Loggers use fire to illegally clear land, mostly for pasture or crops,” he says. And dry season conditions, which occur roughly between June and November, exacerbate the fires, he adds.

More than 39,000 fires have ignited in the Amazon rainforest this year. And the country’s western savannah — Brazil’s most threatened biome — has seen almost 23,000 fires since January.

The number of blazes this year exceeds those for 2016 — Brazil’s worst year for wildfires since 2013 — when the agency’s satellites detected more than 69,000 fires (see ‘Record burn’).

The INPE fire report comes about a month after the institute released figures showing an increase in the rate of deforestation in Brazil. The country’s president, Jair Bolsonaro, accused INPE of lying about the numbers and fired the agency’s director on 2 August.

When asked about the increase in fires during a press conference on 21 August, Bolsonaro accused environmental groups of starting some of the blazes in order to embarrass his administration.

But critics of Bolsonaro say that his push to make the Amazon more accessible to industries such as logging and agriculture is partly responsible for the rise in the number of fires.

Bolsonaro has also hit back at Macron. “I regret that President Macron seeks to instrumentalize an internal issue of Brazil and other Amazonian countries for personal political gains,” he tweeted on 22 August. He characterized Macron’s suggestion to discuss the Amazon fires at the G7 summit as “colonialist” in a subsequent tweet .

German Chancellor Angela Merkel has backed Macron’s call to speak about the fires at the summit, said Steffen Seibert, Merkel’s spokesperson, according to the BBC .

Far-reaching influence

In addition to the environmental impact of the fires, researchers are also worried about the health and climate impacts of the blazes.

A fire that broke out in the state of Rondônia on 19 August produced a huge plume of smoke that spread over thousands of kilometres to São Paulo, Brazil’s most populous city, by mid-afternoon. “The smut produced by wildfires contains fine particulate matter capable of penetrating deep into the lungs and causing severe cardiopulmonary diseases,” says Luiz Augusto Toledo Machado, a meteorologist at INPE.

The particles can also affect cloud-formation and rainfall patterns, says Divino Vicente Silvério, a biologist at the Amazon Environmental Research Institute, in Canarana, Brazil. And that could affect how forests cycle water, he adds. The blazes are also releasing the carbon stored in forests into the atmosphere, which could lead to increases in global temperature, he says.