Quantcast

Climate Change Could Bring Drought to Amazon, Greater Rain to Pacific and African Forests

Climate
Rising carbon dioxide levels could lead to fewer moisture clouds forming over the Amazon rainforest. Ana_Cotta / CC BY 2.0

Scientists have discovered another factor that might interact with rising carbon dioxide emissions to influence climate change—tropical forests.

In a study published in Nature Climate Change Friday, researchers found that the way tropical forests interact with increased atmospheric levels of carbon dioxide could alter rainfall patterns, drying out the Amazon rainforest and increasing precipitation in African and Indonesian forests.


"People tend to think that most of the disruption will come from heat going into the oceans, which, in turn, will alter wind patterns," University of California, Irvine (UCI) professor and study author James Randerson said in a UCI press release. "We have found that large-scale changes in rainfall can, in part, be attributed to the way tropical forests respond to the overabundance of carbon dioxide humans are emitting into the atmosphere, particularly over dense forests in the Amazon and across Asia."

These big effects start with tiny holes. Trees have openings in the underside of their leaves called stomata, which open and close to regulate the amount of carbon dioxide a tree takes in and the amount of water vapor it releases. When there is more carbon dioxide in the atmosphere, the stomata do not need to open as widely, and therefore release less water vapor.

"In many tropical forest regions, the moisture supplied by transpiration, which connects water underground at the root level directly to the atmosphere as it is pulled up to the leaves, can contribute as much as moisture evaporated from the ocean that rains back down at a given location—which is normal rainforest recycling," study lead author Gabriel Kooperman said in the press release.

The researchers used climate models to study how rising carbon dioxide levels would interact with forests to change the climate on various continents.

They found the Amazon rainforest was most at risk of drought and forest mortality due to rising carbon dioxide. Kopperman explained that, as stomata in the Amazon release less water vapor, fewer clouds will form over the forest. This will mean that water vapor from the Atlantic Ocean will not have pre-existing clouds to bond with, and will instead blow over the forest to the Andes.

However, this effect was not predicted to occur in other tropical forests. Forests in Africa and on islands in Malaysia, Papua New Guinea and Indonesia were predicted to see increased rainfall.

On island forests in particular, this is because the reduced moisture will increase temperatures over the islands relative to the surrounding ocean air, pulling in greater moisture from ocean systems.

Kooperman said both drought and floods caused by increased rainfall could have serious consequences both for biodiversity and for food and water access for impoverished populations.

EcoWatch Daily Newsletter

The Rio San Antonio, in the headwaters basin of the Rio Grande in New Mexico, will lose federal protections under a new rule. Bob Wick / BLM California

By Tara Lohan

The Santa Fe River starts high in the forests of New Mexico's Sangre de Cristo mountains and flows 46 miles to the Rio Grande. Along the way it plays important roles for wildlife, irrigation, recreation and other cultural uses, and provides 40 percent of the water supply for the city of Santa Fe's 85,000 residents.

Read More
Climate activists protest Chase Bank's continued funding of the fossil fuel industry on May 16, 2019 by setting up a tripod-blockade in midtown Manhattan, clogging traffic for over an hour. Michael Nigro / Pacific Press / LightRocket / Getty Images

By Julia Conley

Climate campaigners on Friday expressed hope that policymakers who are stalling on taking decisive climate action would reconsider their stance in light of new warnings from an unlikely source: two economists at J.P. Morgan Chase.

Read More
Sponsored
Protesters holding signs in solidarity with the Wet'suwet'en Nation outside the Canadian Consulate in NYC. The Indigenous Peoples Day NYC Committee (IPDNYC), a coalition of 13 Indigenous Peoples and indigenous-led organizations gathered outside the Canadian Consulate and Permanent Mission to the UN to support the Wet'suwet'en Nation in their opposition to a Coastal GasLink pipeline scheduled to enter their traditional territory in British Columbia, Canada. Erik McGregor / LightRocket / Getty Images

Tensions are continuing to rise in Canada over a controversial pipeline project as protesters enter their 12th day blockading railways, demonstrating on streets and highways, and paralyzing the nation's rail system

Read More
padnpen / iStock / Getty Images

Yet another reason to avoid the typical western diet: eating high-fat, highly processed junk food filled with added sugars can impair brain function and lead to overeating in just one week.

Read More
Horseshoe Bend (seen above) is a horseshoe-shaped meander of the Colorado River in Page, Arizona. didier.camus / Flickr / public domain

Millions of people rely on the Colorado River, but the climate crisis is causing the river to dry up, putting many at risk of "severe water shortages," according to new research, as The Guardian reported.

Read More