Want climate news in your inbox? Sign up here for Climate Fwd:, our email newsletter.

Jair Bolsonaro, the strident far-right politician who triumphed in Brazil’s presidential election on Sunday, will not only shape the destiny of Latin America’s largest country. His election is also a referendum on the fate of the Amazon: the world’s largest tropical forest, sometimes known as the lungs of the Earth.

The stakes for the planet are huge.

Mr. Bolsonaro — who once said that Brazil’s environmental policy is “suffocating the country” and on Sunday triumphed in the national election — has promised to champion his country’s powerful agribusiness sector, which seeks to open up more forest to produce the beef and soy that the world demands.

He has stepped back from an earlier suggestion to pull out of the Paris climate agreement, telling reporters last week that Brazil would remain in the deal. Even so, his campaign promises, if carried out, could have dire consequences for the Amazon, and therefore for the rest of the planet. Stretching across two million square miles, most of it in Brazil, the Amazon acts as a giant sink for the carbon dioxide emissions that the world as a whole produces.

Mr. Bolsonaro has said he would scrap the Environment Ministry, which is mandated to protect the environment, and instead fold it into the Agriculture Ministry, which tends to favor the interests of those who would convert forests into farmland.