Smoke billows during a fire in an area of the Amazon rainforest near Porto Velho, Brazil, on August 21. (Ueslei Marcelino/Reuters)

Wildfires raging in the Amazon rainforest have hit a record number this year, with 72,843 fires detected so far by Brazil’s space research center INPE.

The surge marks an 83 percent increase over the same period of 2018, the agency said on Tuesday, and is the highest since records began in 2013.

Since last week, INPE said satellite images spotted 9,507 new forest fires in the country, mostly in the Amazon basin, home to the world’s largest tropical forest, seen as vital to countering global warming.

The Brazilian state of Amazonas declared an emergency in the south of the state and in its capital, Manaus. Acre, on the border with Peru, has been on environmental alert since Friday because of the fires.

Wildfires have increased in Mato Grosso and Para, two states where Brazil’s agricultural frontier has pushed into the Amazon basin and spurred deforestation. Wildfires are common in the dry season but are also deliberately set by farmers illegally deforesting land for cattle ranching.

The unprecedented surge in wildfires has occurred since Brazil’s new president, Jair Bolsonaro, took office in January. He vowed to develop the Amazon region for farming and mining, ignoring international concern over increased deforestation.

Asked about the spread of uncontrolled fires, Bolsonaro brushed off criticism, saying it was the time of the year of the “queimada,” or burn, when farmers use fire to clear land.

People frequently blame the dry season for the wildfires in the Amazon, but that is not quite accurate, said INPE researcher Alberto Setzer.

“The dry season creates the favorable conditions for the use and spread of fire, but starting a fire is the work of humans, either deliberately or by accident,” Setzer said.