The Amazon is on fire. Brazil’s space agency said this week that more than 72,000 fires had broken out across the Amazon rainforest since the start of the year, imperiling one of the planet’s last refuges of biodiversity and raising concern about the region’s ability to combat climate change amid a rollback of environmental protections by the country’s far-right leader. Here’s what you need to know about the destructive blazes and how they could affect the rest of the planet. There are far more fires than usual. Brazil’s space research agency, known as INPE, said this month that as of Wednesday, the Brazilian Amazon had seen 75,336 fires since January. Those numbers far outstrip the number of fires last year and represent more than an 85% increase over 2017. The figures also dwarf those seen in 2016, when there were 67,790 fires by this point in the year. 2016 was linked to a strong El Niño ocean pattern that saw the region face extreme drought conditions, The Washington Post notes.

NASA via ASSOCIATED PRESS This satellite image provided by NASA on Aug. 13 shows several fires burning in the Brazilian Amazon forest. Brazil's National Institute for Space Research said the country has seen a record number of wildfires this year, counting 74,155 as of Tuesday.

The Amazon is often referred to as the “lungs of the planet” The Amazon rainforest is one of the richest areas of biodiversity on the planet and covers 2.12 million square miles. It’s often touted as one of the planet’s biggest oxygen suppliers as well as a key mechanism to absorb carbon dioxide and thereby slow the effects of climate change. The world’s forests suck up 2.4 billion tons of carbon annually, with the Amazon alone absorbing about a quarter of that. But the rainforest’s ability to do so has been weakening, according to a 2015 study. Scientists have warned that even without fires and deforestation, the Amazon won’t be able to keep up with the skyrocketing levels of greenhouse gas emissions released into the atmosphere every year. The blazes aren’t accidental. INPE research Alberto Setzer told Reuters this week that, although fires can be more common in particularly dry years, humans were primarily to blame for the rampant level in recent months. Farmers, emboldened by Brazil’s far-right leader, Jair Bolsonaro, have been setting illegal blazes to clear land for cattle and crops. The Brazilian leader has scaled back his government’s efforts to rein in the destruction, instead promising to open up protected lands to development in order to spur economic growth. “There is nothing abnormal about the climate this year or the rainfall in the Amazon region, which is just a little below average,” Setzer told Reuters. “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,” Mikaela Weisse, a manager at Global Forest Watch, an initiative of the World Resources Institute, told The New York Times this week that natural fires were relatively rare in the Amazon. “So all, or almost all, the fires we are seeing are set by humans,” Weisse told the Times.

#Fires have been #burning in the Brazilian #Amazon for weeks. Smoke from the uptick in fires caused a blackout in #SaoPaulo on Monday. Track the fires in real time and access historical fire data on #GFWFires: https://t.co/HPNol2tNTLpic.twitter.com/MLAzUA2jeM — Global Forest Watch (@globalforests) August 21, 2019

They can be seen from space. The fires have grown exponentially over the past two months during the arrival of the dry season in Brazil. NASA’s Earth Observatory released images of smoke from the fires blanketing the Amazon basin, and the haze grew so bad at one point that it darkened the skies above São Paulo in the middle of the day.

🌎Just a little alert to the world: the sky randomly turned dark today in São Paulo, and meteorologists believe it’s smoke from the fires burning *thousands* of kilometers away, in Rondônia or Paraguay. Imagine how much has to be burning to create that much smoke(!). SOS🌎 pic.twitter.com/P1DrCzQO6x — Shannon Sims (@shannongsims) August 20, 2019

The sudden darkening prompted an outcry on social media, with some residents declaring the “apocalypse” had come while others organized around the hashtag #prayforamazonia. Environmental groups link them to the policies of Brazil’s far-right leader. Bolsonaro has been in power only since January, but the Amazon had already lost more than 1,330 square miles of forest cover by July as the Brazilian government pulled back on enforcing environmental policies, the Times reported last month. Environmental groups have cast the Bolsonaro government’s policies as a driving force behind the destruction in the Amazon. “The unprecedented fires ravaging the Amazon are an international tragedy and a dangerous contribution to climate chaos,” Christian Poirier, the program director of Amazon Watch, an environmental nonprofit, said in a statement. “This devastation is directly related to President Bolsonaro’s anti-environmental rhetoric, which erroneously frames forest protections and human rights as impediments to Brazil’s economic growth. Farmers and ranchers understand the president’s message as a license to commit arson with wanton impunity, in order to aggressively expand their operations into the rainforest.”

Queimadas e desmatamento na Amazônia. Por que acontece? O que você pode fazer para ajudar? Uma thread. (Foto de Outubro/2018) pic.twitter.com/vlxc8oHna0 — Greenpeace Brasil (@GreenpeaceBR) August 21, 2019