The Amazon rainforest hosts the richest biodiversity of any ecosystem on the planet, providing habitat for one out of every ten known species.
However, as mining, logging and agriculture encroach deeper into the Amazon, people are increasingly exposed to its wildlife — and the diseases they may carry.
If deforestation continues to accelerate, the Amazon could be at risk of becoming ground zero for the world’s next pandemic, according to a study published today.
Conservation News spoke to one of the paper’s lead authors, Conservation International scientist Lee Hannah, about the links between deforestation and disease — and why protecting the world’s biggest rainforest is crucial to preventing future pandemics.
Question: What do pandemics have to do with nature?
Answer: Over the past century, two new animal-borne viruses have emerged from nature every year — and these numbers are set to increase over the next decade. The leading driver of zoonotic diseases— which jump from animals to humans — is deforestation. When people cut down forests to make room for roads, farms or cattle, they are also creating new edges of the forest, and increasing their exposure to animals with diseases that can infect them — a process known as “virus spillover.”
Unfortunately, there has been a surge of tropical deforestation in recent years, with nearly 12 million hectares (52 million acres) of tropical forest loss in 2019 — equivalent to the planet losing a soccer-field sized chunk of tropical forest every six seconds. The Amazon alone lost an estimated 2 million hectares (5 million acres) of forest in 2020, increasing the risk of virus spillover.
Q: With that much deforestation, why hasn’t the Amazon already been the source of a pandemic?
A: Frankly, we’ve been lucky. There are several highly deforested areas in the Amazon that can already be considered at high risk for infectious disease spillovers. And if tropical deforestation continues to accelerate, these high-risk areas could expand. We found that even a small amount of deforestation — especially if it occurs in pristine, previously undisturbed areas — could have a disproportionate impact on the chances that a zoonotic virus such as COVID-19, Ebola or bird flu could emerge. Using a new model in our study, we found that without stronger policies to protect the Amazon, more than 40 percent of many of the Amazon’s intact forest areas could be chopped down by 2050.
Not only could this level of deforestation in the Amazon increase the risk of future pandemics, it could be catastrophic for the climate. If the Amazon becomes too degraded, the forest will reach a “tipping point” where it loses its ability to generate its own rainfall, gradually — and irrevocably — turning into dry savanna. This transformation could negatively affect the Amazon’s ability to store planet-warming emissions, support native species and provide resources such as fresh water and food to local communities.
Luckily, there is still time to prevent the Amazon from reaching this tipping point and reduce the risk of future pandemics.
A: The best place to start is by recommitting to strong anti-deforestation policies in Brazil and replicating those policies in other Amazonian countries. These efforts do not have to come at the cost of economic growth. For example, in 2004, Brazil launched a set of policies that eliminated unproductive subsidies and reduced deforestation in the Amazon by about 70 percent between 2005 and 2012. Economic growth during that period rose by 141 percent.
Policies to protect the Amazon must also include the formal recognition of Indigenous lands, which cover more than one-third of the Amazon region. Overall, lands that are owned, used or occupied by Indigenous peoples show less species decline and pollution, and better-managed natural resources, research shows.
But preventing disease spillover from the Amazon is not solely the responsibility of Brazil, Colombia, Ecuador and other Amazonian countries; it is going to take action at a global scale. In a recent study I co-authored, we found that reducing deforestation, regulating the global wildlife trade and monitoring the emergence of new viruses worldwide could reduce the risk of future pandemics by 27 percent or more — with a 10-year investment that is 50 times less costly than coronavirus response efforts to date. By investing in prevention now we can save countless lives — and trillions of dollars — down the line.
Cover image: The Brazilian Amazon (© Flavio Forner)