Reviews explore the drivers and impacts of Am

In two separate Reviews, researchers underscore the rapid and profound changes occurring in the Amazon resulting from ever-increasing human activity. They discuss what’s known about the drivers and impacts of the ongoing deforestation and landscape degradation the region is experiencing, and what needs to be done to avert the worst outcomes. The Amazon rainforest is among the most vital yet vulnerable major ecosystems on Earth. It provides crucial global ecosystem services that help maintain the planet’s carbon and water cycles and plays host to nearly one-third of all known species on Earth. However, modern agricultural and industrial activities and broader anthropogenic changes in the planet’s climate are degrading Amazonian environments at an unprecedented pace. Teetering at the precipice of irrevocable change, continued forest loss threatens to push the Amazon past a critical threshold that could have far-reaching implications for the whole Earth system.

In one Review, James Albert and colleagues summarize key findings from the 2021 Science Panel for the Amazon (SPA) Assessment Report and show how human activities like regional deforestation are changing Amazonian ecosystems at rates hundreds to thousands of times faster than any naturally occurring climatic or geological phenomena have in the past – far too rapidly for Amazonian species, peoples, and ecosystems to adapt. According to Albert et al., transformative policy actions are required to prevent these outcomes and reduce the global economic demands that largely drive deforestation. “As we approach an irreversible tipping point for Amazonia, the global community must act now. Policies to prevent the worst outcomes have been successfully identified; implementation is only a matter of leadership and political will,” write Albert et al. “To fail the Amazon is to fail the biosphere, and we fail to act at our own peril.”

In a second Review, David Lapola and colleagues evaluate the proximate and underlying drivers and consequent impacts of Amazon forest degradation. While most analyses of land-use and land-cover change in tropical forests have centered on the causes and effects of deforestation, Lapola et al. focus on other, lesser-studies anthropogenic disturbances, including fire, habitat fragmentation, selective logging, and extreme drought due to human-induced climate change. According to the authors, roughly 2.5 million kilometers of the Amazon forest (roughly 38% of all remaining forests in the region) are currently degraded by these impacts. Carbon emissions from this degradation are equal to, if not greater, than emissions from deforestation and will remain a dominant source of carbon emissions regardless of deforestation rates. As a result, Lapola et al. argue that not only are deforestation policies needed, but they must also be complemented with measures to address the disturbances that degrade the Amazon environment.

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