It wasn’t until heavily armed men arrived from across the river that Cláudio José da Silva realized who was bankrolling the latest episode of illegal logging. His bare chest traced with blue-black lines of body paint, da Silva is a member of the Guajajara people in eastern Brazil, one of the country’s largest indigenous groups. Their side of the Carú River is pristine Amazon rain forest. Across the river, the rain forest has been razed and replaced by cattle ranches and farms. On paper, the Guajajaras’ nearly 700 square miles of rain forest are protected as federally recognized indigenous territory. In reality, the group lives under constant threat of theft and violence. Just the day before, da Silva’s self-defense force, the Guardians of the Forest, caught the local sheriff’s son using cattle to drag lumber from their forest. Armed with machetes, they chased him away and confiscated the cows. Now the sheriff had come bearing an ultimatum: Return the cattle or his posse would retrieve them by force.
“This struggle, for us, is war,” da Silva says. He claims to have received dozens of death threats since founding the Guardians of the Forest in 2012. “The loggers carry arms. The farmers are armed. They want confrontation.” Indeed, on August 12, a month after I visited da Silva, the dead body of his comrade, Jorginho Guajajara, was found in a nearby river.
Violent conflicts over land and logging have spilled blood throughout the Amazon since the 1980s, when the murder of the organizer Chico Mendes made international headlines. Brazil is the deadliest country in the world for land defenders, with more than 140 killings since 2015, according to the NGO Global Witness. The state of Maranhão, where the Guajajara live, is perhaps the most dangerous: In 2016, more attacks on indigenous groups occurred there than anywhere else in Brazil, according to the Pastoral Land Commission.
Apart from the human toll, the violence in the Amazon is also driving an ominous trend in the earth’s climate system. Last October, Science published one of the most important—and least noticed—climate studies in years. Tropical forests in the Amazon and around the world have been so degraded by logging, burning, and agriculture that they have started to release more carbon than they store, according to scientists from the Woods Hole Research Center and Boston University. In the parlance of climate change, these forests are flipping from carbon sinks to carbon sources.
This is very bad news, for two reasons. First, until now, the capacity of forests to absorb carbon dioxide via photosynthesis has been a crucial buffer against greenhouse-gas emissions: The forests’ absorption of CO2 has limited the global temperature rise to considerably less than it would otherwise be. Second, forests must absorb even more carbon going forward if humankind is to contain that temperature rise to a survivable amount. Current trends put the earth on a trajectory to an increase of 3.5 degrees Celsius, an amount that scientists have warned is “incompatible with organized society.” Minimizing future emissions is imperative, but it’s not enough. To meet the Paris Agreement’s commitment to hold the temperature rise “well below” 2°C, humankind must also “go negative.” That is, we must extract the CO2 that’s already in the atmosphere and store it where it can no longer trap heat, notably in the earth’s trees and soil. And that means growing more trees, not cutting them down.