One of the world’s most diverse ecosystems, the Amazon is home to 1 in 10 known plant and animal species on Earth. The rainforest also helps protect the planet from climate change. Its trees absorb massive amounts of carbon dioxide (CO2), a heat-trapping gas that would otherwise enter the atmosphere and raise Earth’s temperature.
But over the past 20 years, the atmosphere above the Amazon has been drying out. Rising levels of greenhouse gases, along with the fires and deforestation, have made the Amazon region warmer.
In the rainforest, trees draw water from the soil and then release it as vapor that cools the air and forms clouds. Clouds produce rain. But as temperatures have increased, plants have needed more water—while the soil has had less moisture to give them.
Meanwhile, as people clear land in the Amazon, the trees they chop down release stored CO2 into the atmosphere. Fires produce soot, which increases global warming. And whatever takes the place of rainforest— typically livestock and crops—results in more greenhouse gases. All of this further raises temperatures—and increases the need for more water.
If these patterns continue, parts of the Amazon won’t be able to generate enough rainfall to survive, says biologist Thomas Lovejoy.
Once that happens, “the vegetation will convert to savanna, with immense loss of biodiversity,” he says. As trees die off, huge amounts of CO2 will be released into the atmosphere. And the 30 million people who live in the Amazon rainforest—including Indigenous groups—will be severely impacted.