The Amazon Rainforest Was Once a Human Success Story. It Could Be Again

A season of intense, human-caused wildfires in the Amazon rainforest has scorched thousands of square miles of forest, blackened the skies over São Paulo, and sparked international concern about the fate of the most biodiverse landscape on the planet.

Tens of thousands of independent wildfires have been deliberately set by humans in the Amazon this summer, making the destruction of the rainforest a purely anthropogenic phenomenon egged on by the far-right regime of Brazilian President Jair Bolsonaro. To some, this may make it seem as if the presence of people in the Amazon is inexorably linked to the rainforest’s ruin. But this viewpoint overlooks the deeper, and deeply human, past of the rainforest. To restore the Amazon in the future, it will be essential to look to that past, and humanity’s persistent role in it, for guidance.

In recent years, scientists have accumulated a wealth of evidence demonstrating that the Amazon was shaped by people long before European colonizers set foot in it. Indigneous peoples, who arrived in the rainforest at least 10,000 years ago, altered the ecological landscape of the biome on a scale that has largely gone unappreciated, turning it into an important air purifier for Earth’s atmosphere.

“Amazonia has long been understood as a ‘natural’ space occupied mostly by virgin forest,” said Helena Pinto Lima, researcher and curator of archeology at Museu Paraense Emílio Goeldi in Belém, Brazil, in an email. “This pervading myth of a pristine rainforest has blinded many to what has been increasingly shown to be a cultural landscape.”

In contrast to the modern devastation of the rainforest, ancient populations created a more biodiverse and fertile Amazon over the course of countless generations. Archeologists have barely started to untangle the mysteries of this complex Pre-Columbian civilization, but recent evidence suggests the Amazon was populated by several million people before the arrival of Europeans.

Amazonian tribes were decimated by diseases and genocide in the wake of European colonization as well as horrifying bouts of violence in subsequent centuries. Some populations have begun to recover in recent decades, and roughly one million Indigenous people live in the Brazilian Amazon today. Some groups number in the thousands, such as the Guajajara or Ticuna people, but there are also communities that contain fewer than 100 individuals, according to the Instituto Socioambiental, an Indigenous rights and research center based in São Paulo.

Some tribes have remained isolated and uncontacted in the forest. Even those that have established strong social connections to non-Indigenous communities often continue the traditional practices of their ancestors. While the rainforest certainly existed when the first Indigenous people settled there, much of the Amazon’s lush wildlife and carbon-storing powers are a direct result of these traditions, which include plant domestication, controlled fires, and soil enrichment.

“What we’re seeing with the Amazon is not so much ‘culture versus nature’ but rather a dispute between two different modes of human occupation,” said Gabriel Soares, who is pursuing a PhD in anthropology at the National Museum of Brazil in Rio de Janeiro.

“One has produced, over the course of thousands of years, this extremely diverse biome which has contributed immensely and in many different ways to the habitability of the planet,” he continued. “The other, which causes the fires that you’re seeing, can potentially have a gigantic negative impact on the planet as a whole.”

Scientists have reconstructed some of the rainforest’s ancient anthropogenic history by surveying local plant species at thousands of archeological sites. A 2017 study published in Science found that plants domesticated by Indigenous populations—such as the brazil nut, maripa palm, and cacao tree—are about five times more plentiful near these bygone settlements.

“The closer to an archeological site, the more likely a given plot was to have a high abundance and a high richness of domesticated fruit trees and palms,” said Charles Clement, a biologist at the National Institute of Amazonian Research in Manaus, Brazil.

Many of the crops favored by Indigenous populations are particularly adept at sucking carbon out of the atmosphere. One study estimated that the Brazil nut tree, which can grow to 160 feet tall and live for 1,000 years, contains 1.3 percent of the Amazon rainforest’s carbon by itself.

The implications of this domestication process transcended lifetimes and have played out over thousands of years, creating a carbon-storing biome that is an essential bulwark in efforts to mitigate the climate crisis. Brazil nuts, palms, and other crops also helped foster the Amazon’s unparalleled biodiversity, as fruits and nuts opened new niches to native wildlife species.

“The Amazon forest can be considered a natural-cultural heritage site of global importance, because the Amazonian forests hold legacies of their interactions with humans and many other species,” said Carolina Levis, an ecologist at the Federal University of Santa Catarina in Florianópolis, Brazil, in an email.

One important example of the impact of Indigenous peoples on the Amazon is terra preta, a type of black soil created by millennia of human habitation, which is partly a byproduct of charring biomass. When deposited alongside the compost, manure, pottery, and dead biomatter generated by ancient settlements, the charred mix enriched the Amazonian soil with nutrients.

Levis emphasized that there is a huge difference between the modern “slash-and-burn” techniques that are decimating the Amazon and the charring practices used by Indigenous populations to manage the rainforest environment and produce terra preta.

“We need to differentiate illegal use of fire to open space for agribusiness and other large-scale agricultural activities from traditionally prescribed and controlled fire for diverse local activities,” she explained. “We have a lot to learn from Indigenous societies who have developed such sophisticated practices of fire management without causing large-scale deforestation.”

Indigenous methods tend to involve creating small, smoldering fires from plant biomass that are covered with dirt or straw and rotated around different patches of land each season. Not only does this approach reduce the risk of uncontrolled wildfires, it captures half of the biomass carbon in the ground, which prevents the release of greenhouse gases. One 2006 study suggested that up to 12 percent of human-caused carbon emissions could be offset by switching from slash-and-burn to "slash-and-char."

Terra preta, besides being a boon for the climate, is also considered to be one of the most nourishing soils on Earth, and benefits farmers today.

“People today look for those soils to do agriculture,” said Eduardo Góes Neves, an archeologist at the University of São Paulo, in a call. “They are very productive and they have something which is very interesting for the tropics—they are very stable. They don’t leech. They don’t lose nutrients.”

It is an amazing example of local traditions producing global benefits. Sadly, many of the ancient sites that show strong signs of Indigenous influence are clustered in the southern Amazon, which is now undergoing a very different type of anthropogenic transformation: Rapid deforestation and harsh wildfires.

“The fires that are burning happily across [southern] Amazonia are precisely the areas that are expected to have very anthropogenic forests,” Clement noted.

The majority of the fires were set to clear space for farms, ranches, and other forms of resource extraction. While this process repeats every year in the Amazon, the 2019 season has been particularly intense because Bolsonaro refuses to enforce environmental laws and protections. As a result, deforestation accelerated leading up to the fire season, which exacerbated the resulting disaster.

“During Bolsonaro’s campaign and the first seven months of his administration, he’s made it clear that this kind of illegal activity is acceptable in the Amazon,” Clement said.

Most tragically, the devastation poses an existential threat to the same Indigenous cultures whose traditional practices have so enriched the rainforest.

Such risks to Indigenous lives, lands, and livelihoods are not unexpected, given that Bolsonaro ran a campaign that was openly hostile to the rights of tribes and communities that live in the rainforest.

“Bolsonaro has this terrible reputation across the world and he deserves to have it because he’s a terrible person,” Neves said. “If there is anything good about this, it’s to show us that when these guys take over, this is the world we’re going to live in. There’s nothing related to construction, compassion, or looking to the future. Only destruction.”

Rebukes of Bolsonaro, both inside and outside Brazil, have placed uncomfortable pressure on his administration. Bolsonaro has become so indignant about the backlash that he floated a story, without evidence, that NGOs are behind the especially fiery season.

This plays into paranoid conspiracy theories that distort the motives behind partnerships between conservation organizations and Indigenous groups. The attempt to muddy the waters with disinformation was reflected in a leaked government presentation that argued for the immediate construction of megaprojects, such as highways and bridges, to head off international efforts to protect the Amazon.

In reality, conservation groups often advocate for the empowerment of Indigenous people—not only in Brazil, but around the world—because there is a large body of evidence linking Indigenous practices to better conservation outcomes.

“Investing in Indigenous communities to develop their own plans for managing natural resources is vital to quelling this chaos in the largest rainforest on Earth,” said Alex Antram, conservation outreach manager at Rainforest Trust, a US-based nonprofit that has protected more than 23 million acres of rainforest worldwide.

These partnerships are complicated by the chaotic land management system in the Amazon rainforest, which is rife with fraudulent property titles and land speculation schemes. When combined, all of these forces have placed Amazonian communities in danger, not only of fires, but of physical assault and murder.

“Because of the current policies, [there are] increasing trends toward violence, especially along the expanding agricultural and extractive frontiers,” Lima said.

Many Indigenous people, and groups that support them, hope that the international focus on the Amazon fires will spur renewed efforts to protect demarcated Indigenous territories. Preserving the Amazon also depends on much stronger enforcement of environmental laws and the implementation of Indigenous land and forestry management on wider scales.

“We say no to mining in our lands, no to deforestation,” said O-É Kaiapo Paiakan, a member of the Xinguan Indigenous group, in a recent video posted by Instituto Socioambiental. “No more invasions and disrespect. No more pesticides in our rivers and foods. No more criminal fires in the forest. We are with you, standing for the Amazon.”

Neves had just returned from the field when I spoke to him, and had seen the harrowing effects of the deforestation and wildfires up close. However, he also felt encouraged by how the disaster has galvanized Brazilians to support the natural and cultural preservation of the rainforest.

“I see a lot of destruction and fire, mostly in the southwest Amazon, but also you see a lot of people doing wonderful things like agroforestry, or Indigenous people getting politically stronger and having their voices heard,” Neves noted.

“Indigenous people are the ones who can show us the way to have this wonderful forest back,” he said. “I think there is hope.”