Brazilians vote to elect a president on October 2, and Luiz Inácio Lula da Silva, a former president and the Workers’ Party candidate, is leading in the polls. But the current president, Jair Bolsonaro, is threatening to disregard the results and seize power. If that happens—or if Bolsonaro somehow wins at the ballot box—it will accelerate the destruction of the Amazon rain forest. Brazil is skidding toward an environmental disaster, and if Bolsonaro remains in power, his government will sabotage the international campaign to slow global warming. It is no exaggeration to call the next election in Brazil one of the most important votes in environmental history.

Scientists are making alarming new predictions. They say that the destruction of the Amazon, which makes up more than half of the world’s remaining rain forests, could be approaching the point of no return. Thomas Lovejoy, the legendary ecologist who died last year after devoting his life to preserving the region, joined with a Brazilian colleague, Carlos Nobre, to warn that once 20 to 25 percent of the Amazon is cut down and burned, the changes to the regional climate could push much of the remaining forest past a “tipping point.” No matter what happens after that, the rain forest would convert to barren scrubland.

One estimate is that as much as 17 percent of Amazonia has already been destroyed—which is awfully close to 20 to 25 percent. If you look beyond the measured language in this 2021 scientific study, the implications are terrifying: “The Amazon is estimated to contain about 123 billion tons of carbon above and below ground, and is one of Earth’s most important terrestrial carbon reserves. As global fossil-fuel burning has risen, the Amazon has absorbed CO2 from the atmosphere, helping to moderate global climate. But there are indications…that the Amazon’s capacity to act as a [carbon] sink may be disappearing.”

(Other scientists, although fearful of the destruction, contend that the tipping point may not be quite as imminent. In response, Lovejoy used to say, “Multiply the risk of a catastrophe in the Amazon by its disastrous consequences and you will see that inaction is impossible.”)

Alarmed members of the US Congress are starting to pay attention. Senator Bernie Sanders is gathering support for a Senate resolution to warn Bolsonaro that the United States will break ties with Brazil if he illegally holds on to to power. In the House, Representative Tom Malinowski (D-N.J.) is leading a similar effort, which would cut off US military aid.

It is the burning season in Amazonia. On August 22, satellites detected 3,358 fires across the region. The blazes are no accident. They are deliberately set to convert the forest into cattle pasture, often for large agribusinesses and ranchers, who are among Bolsonaro’s staunchest supporters. Christian Poirier, program director for the environmentalist group Amazon Watch, points out that the Bolsonaro government dismantled and sabotaged the state agencies that are supposed to protect the Indigenous rain forest dwellers. “The forest defenders have been attacked as never before,” he told me. “Bolsonaro has let the bloodletting go completely unchecked. In fact, he’s encouraged it.”

A stunning new documentary, The Territory, shows the danger on a human scale. The film takes a several-years-long look at the Uru Eu Wau Wau people in Rondonia state, whose protected reserve is being invaded and burned with impunity by the land-grabbers. One of the young Indigenous leaders, Ari, was murdered during the making of the film. Neidinha Bandeira, an environmentalist who is one of the film’s heroes, points out that while those who destroy the forest with chainsaws and firebrands are poor people from elsewhere in Brazil, it’s the cattle ranchers who sponsor them and who will seize the lands for their herds.

It may come as a surprise that Brazil sends beef to the United States. Exports spiked in the past two years, registering a 57 percent increase this past January alone. The meat imports give the US potential economic leverage to help protect the Amazon.

Ana Carolina Alfinito, a legal adviser at Amazon Watch based in Brazil, said that Bolsonaro’s environmental record should inspire dread. “There was a 50 percent increase in deforestation in the past three years. Some 10,000 square kilometers a year were burned or cut down, with catastrophic impact on biodiversity, on human lives,” she told me. “The ‘best case scenario’ if he stays in power is that conditions in Amazonia will only stay as catastrophic as they are already.”

Fortunately, the mainstream American and European media are starting to report on the destruction. After British journalist Dom Phillips and his Brazilian guide, environmentalist Bruno Pereira, were murdered during a reporting trip to the region’s far northwest in June, a New York Times reporter retraced their journey. Other long articles showed how the Bolsonaro government slashed the budgets of the government agencies supposed to stop deforestation and how hundreds of illegal airstrips have been built in the Amazon to facilitate illegal mining.

Environmentalists, in Brazil and elsewhere, say Bolsonaro’s socialist adversary, Lula, had a good (though not perfect) record on the Amazon during his eight years in office. Rain forest deforestation trended considerably downward when he was president.

But, so far, Bolsonaro’s threats to hold on to the presidency even if he loses the election have not been taken seriously enough. Outside Brazil, he’s sometimes regarded as a bombastic clown or as a hapless incompetent whose mishandling of the Covid crisis resulted in the death of nearly 700,000 Brazilians, the second-highest toll in the world—after that of the United States.

Michael Fox, an American journalist who has worked in Brazil for seven years, has a more sinister view. He called Bolsonaro a “fascist” who is skillfully using violence and racism to stoke armed mobs of his supporters. Fox, who is making his argument in a podcast series called Brazil on Fire, worries that Bolsonaro will use his street fighters and his allies inside the army to create so much unrest during or after the election that he can either ask for military intervention or otherwise remain in power indefinitely. If no candidate wins more than 50 percent in the first round on October 2, the top two vote-getters—who will almost certainly be Lula and Bolsonaro—will face off again in an October 30 runoff. This could give Bolsonaro and his supporters even more time to try to make the country ungovernable.

Meanwhile, Lula has just floated an intriguing new environmental plan. He is proposing that Brazil ally with other leading rain forest nations—Indonesia and the Democratic Republic of Congo—“to push for resolutions to help developing countries preserve their forests and pressure rich countries into contributing to the cost.” Any credible efforts to push the rich world to help pay to protect the rain forest will increase support for environmentalism in Brazil and elsewhere in the Global South.

None of this will happen if Bolsonaro overturns the election. Bolsonaro won’t just be a dictator repressing his own people. He will be fueling global environmental catastrophe.