Scientists Raise Alarms About the Destruction of the Amazon

January 26, 2023

By Bonnie Eissner

Unprecedented clearing of the world’s largest rainforest must be halted, researchers assert.

Pedro Val Science Review paper on the Amazon
In a "Science" article, two Graduate Center professors join 17 other scientists in warning of the unprecedented, human-induced change in the Amazon. (Credit: Getty Images)

The deforestation of the Amazon is drawing worldwide attention and concern. Already, 17% of the world’s largest rainforest, a cradle of biodiversity and driver of climate and weather patterns, has been cleared away.

In a new review paper in the journal Science, 19 scientists including Professors Ana Carnaval (GC/City College, Biology) and Pedro Val (GC/Queens, Earth and Environmental Sciences) detail the unprecedented rate at which people are altering the Amazon, which outstrips the abilities of the region’s species, people, and ecosystems to adapt. To avert the worst outcomes, including that the lush rainforest could transform into a degraded savannah-like environment, the scientists propose several policy solutions.

“The rate of change of what is forested in the Amazon has been too fast,” said Carnaval, the second author on the paper, "and this is serious, not just for Amazonia, but for our planet as a whole.”

The gradual evolution of the Amazon over millions of years contributed to its vast biodiversity, said Val, a geologist. “If you take those slow geologic rates and compare those to the velocities that humans clear forests and export nutrients and use the soil — that kind of thing — then you start seeing that the velocities that we operate at are way faster than anything natural,” he said.

Learn More About the Ph.D. Program in Earth and Environmental Sciences

Both Carnaval and Val are from Brazil and contributed to the 2021 Science Panel for the Amazon Assessment Report on which the Science article is based.

Pedro Val Science Review paper on the Amazon
Illegal mining has been expanding during the last decade along rivers towards the north of the National Park of Canaima, Venezuela — part of the Amazon basin. River quality has been heavily affected, and no legal measures have been implemented to halt this deterioration. (Photo credit: Suzette Flantua)

The Science paper authors found that people in the region and around the world are altering Amazonian ecosystems at rates hundreds to thousands of times faster than those of natural processes. Put more starkly, people are inducing drastic changes in the time frame of decades to centuries as compared with millions to tens of million of years for evolutionary, climatic, and geological processes. The region faces a host of threats brought on by agriculture, mining, and urbanization, which involve clearing the forest, damming and polluting rivers, and introducing foreign species, and by global climate change that is spurring forest fires and floods.

What if the Amazon Reaches a Tipping Point

“Widespread Amazon deforestation would be an irreversible catastrophe for the global climate system,” the paper authors write. For one, releasing all the carbon stored in the Amazon could cause the Earth’s average temperature by about half a degree Celsius, they note.

The Amazon is home to more than 10% of all named plant and animal species, and the high rates of environmental change in the region jeopardize their survival, the authors point out. The diminishing biodiversity and resilience of the Amazon in turn pose challenges to global civilization.

Ana Carnaval
Ana Carnaval

“The Amazon plays a fundamental role in balancing the climate and providing ecological services that the entire planet benefits from,” Carnaval said. “If we lose this habitat, this ecosystem, we are not only bringing some bad news to the local species, but also to the sustainability of local human populations, and to the global climate, especially in the Americas.”

The scientists raise concerns that the region is approaching a tipping point. “Beyond a certain threshold, deforestation and regional aridification will become locked in a vicious cycle that drives a runaway transformation of lush rainforests to degraded savannah-like landscapes,” they write.

The Steps to Sustainability

Pedro Val
Pedro Val

To avert this dire outcome, the authors recommend several policy approaches. They call for legal tools that criminalize activities that damage or destroy Amazonian ecosystems or that harm the health and well-being of Amazonian species. They note the urgent need for new economic policies that support the more than 40 million people who inhabit the region in environmentally sustainable ways. They also advocate for transitioning from fossil fuels to a post-carbon global economy.

To Val, enacting policies that prevent deforestation is the top priority. “Once you remove vegetation, you leave all these other things unprotected,” he said. “Then you can’t regrow trees, and it’s just this cascading effect of degradation. So the first order of business definitely is to zero deforestation.”

Carnaval echoes this and says the most chilling aspect of deforestation is the growing network of roads in the Amazon that stems from the drive towards urbanization and exploitation of resources. “Over time, you just can see the increasing level of habitat loss — the forest base converted to urban areas,” she said. “These roads now allow people to access areas that were previously pristine.”

Brazil’s New Government Spurs Hope

With 60% of the Amazon located in Brazil and the recent election of President Luiz Inácio Lula da Silva, Carnaval and Val are optimistic that deforestation can be halted. “They’ve done it before,” Val said. “They got close to zero deforestation, and so I think the pressure should definitely be towards that direction.”

Val grew up in Manaus, Brazil, in the heart of the Amazon. Trained in geomorphology and geology, he studies landscapes, which he terms the skin of the Earth — the interface between solid earth and atmosphere — and his recent research has centered on the Amazon. “Being from the Amazon is definitely pushing me to appreciate this sense of belonging to the geographic region where you do research,” he said. “It has become a personal objective, sort of a career-long objective, to produce knowledge about the Amazon.”

Carnaval, who is from Rio de Janeiro, studies biodiversity and evolution in South American forests, which include the Amazon as well as Andean forests and Atlantic forests, where she currently focuses her work. She believes that the Amazon can be reforested and says that the timing of the Science paper is crucial in spurring meaningful policy change in and beyond South America.

Learn More About the Ph.D. Program in Biology

“I think that we could definitely halt the destruction of new areas and that we are absolutely able to restore what we have lost,” she said. The Amazon is still enormous and can provide the materials needed to revive deforested areas, the professor said. But, she added, repairing and even protecting the Amazon demand the cooperation of people around the world.

“If we want to preserve a large tropical forest that is crucial to balancing the climate of our planet, then we need to make choices,” Carnaval said. “We shouldn't be promoting the extraction of products from the system if it's going to lead to destruction. So there's this very important message that spins out of the paper that is really about market behavior. How will the international community work, or the funding community work to avoid further exploitation of the forest, the further conversion of the habitat?”

Published by the Office of Communications and Marketing