I N THE MIDDLE of the afternoon on August 19th South America’s largest city went dark. Under a thick, black cloud at 3pm, the lights flickered on in São Paulo’s skyscrapers; on the motorways brake lights started to glow in the city’s bumper-to-bumper traffic, and many Paulistanos were worried. Social-media users posted pictures of the gloom, juxtaposing the dystopian afternoon sky with fictional apocalyptic places such as Gotham City from “Batman”, Mordor from “Lord of the Rings” and “the upside down” from “Stranger Things”.

Meteorologists scrambled to explain what was going on. But the most likely explanation, most accept, is that fires burning far away in the rainforest are to blame. Climatempo, a popular private meteorology website, reported that a cold front brought low-lying clouds which then combined with smoke to form the thick black smog. According to the National Institute for Space Research ( INPE ), forest fires are more common than ever. The number detected so far this year is 84% higher than in the same period last year. Just over half of the fires are in the Amazon.

During the Amazon’s dry season, it is common for farmers to set fires illegally to clear land. Brazil’s populist president, Jair Bolsonaro, has encouraged them by weakening the agencies that enforce environmental regulations. He holds the view that protecting the forest hinders economic development. When asked about the fires, he ludicrously responded by accusing environmental NGO s of setting the fires themselves so as to make his government look bad, in retaliation for his cuts in their funding.

Mr Bolsonaro argues that he is fighting an “information war” over the Amazon; he says he wants foreign governments and NGO s to stop meddling in Brazil. After INPE released data showing increasing deforestation in July, the president claimed the numbers were fake. He then sacked the head of the agency, Ricardo Magnus Osório Galvão, a well-respected physicist.

Such belligerence outrages scientists and environmentalists. “Firing the director is an act of revenge against those who expose the truth,” says Marcio Astrini of Greenpeace, a pressure group. But the destruction of the rainforest tends to be out of sight, out of mind for a lot of Brazilians, most of whom live in large cities near the coast. The darkness brought deforestation to their doorsteps. “We don’t have much time,” a columnist wrote in the daily newspaper Folha de São Paulo. “Night will fall on all of us.”■