Quantcast

NASA Satellite Images Show Climate Change Accelerates ‘Browning’ of Congo Rainforest

Climate

The Congo—one of the world’s greatest rainforests—is getting steadily less green. The slow change in color during this century, recorded by a series of U.S. satellites, has been matched by a rise in temperature and lower precipitation. And, researchers think, it could reflect a forest’s response to climate change

Scientists from Australia, China, the U.S. and France report in the journal Nature that they examined optical, thermal, microwave and gravity data collected by orbiting sensors between 2000 and 2012.

The new study used satellite data from NASA to track the gradual "browning" of the Congolese rainforest.

They concentrated on intact forested regions during the months of April, May and June each year, which span the peaks of growth and rainfall. They detected an intensification in the forest’s decline. This decline was consistent with lower rainfall, poorer water storage below the canopy and a gradual change in the composition of species.

“It is important to understand these changes because most climate models predict tropical forests may be under stress due to increasing severe water shortages in a warmer and drier twenty-first century climate,” said Liming Zhou, of Albany State University of New York. But other factors could accelerate this “browning” of one of the world’s greatest rainforests.

A team from the Catholic University of Louvain in Belgium—also known in Belgium’s other language as KU Leuven—predicts in the Journal of Climate that explosive population growth and inefficient agricultural practices are likely to make things a great deal hotter for the region and a great deal worse for the rainforest.

By 2050, according to their computer models, Central Africa will be on average 1.4 degrees Celsius hotter than it is today just because of greenhouse gas emissions. And the steady destruction of the forest will add an extra 0.7 degrees Celsius to that figure.

Temperature increases on such a scale will harm plant and animal species and even bring about some extinction. Where the forests have been cleared, there will be increased levels of evaporation, and consequent rises in temperature.

Across the Atlantic, things also look bleak for the Amazon rainforest. Paulo Brando of the Amazon Environmental Research Institute in Brazil and colleagues from the U.S. report in the Proceedings of the National Academy of Sciences that the piecemeal clearing of the rainforest, along with drought, has begun to create “tinderbox” conditions  and an ever more destructive cycle of burning.

Over the course of eight years, in one of the longest-running experiments of its kind, the researchers burned 50-hectare plots of forest in the south-eastern Amazon, a region vulnerable to climate change. They compared the tree deaths each year to measure the impact of drought on fire intensity.

“Drought causes more intense and widespread fires,” said Dr. Brando. “Four times more adult trees were killed by fire during a drought year, which means that there was also more carbon dioxide released into the atmosphere, more tree species loss and a greater likelihood of grasses invading the forest.”

This research, too, was backed up by satellite observation. In 2007, a year of drought, fires in south-east Amazonia burned 10 times more forest than in an average year—an area equivalent to a million soccer fields, according to Douglas Morton of the U.S. space agency NASA, a co-author.

Climate change is expected to bring shorter, more intense rainy seasons and longer dry seasons in the region. Michael Coe of Woods Hole Research Center, another author, said “We tend to think only about average conditions, but it is the non-average conditions we have to worry about.”

--------

YOU MIGHT ALSO LIKE

Climate Change Causes Chain Reaction in Ecosystems

Importance of Old Growth Forests: Carbon Capture Potential Grows With Age

Bamboo: The Secret Weapon for Forest Restoration? 

--------

EcoWatch Daily Newsletter

New pine trees grow from the forest floor along the North Fork of the Flathead River on the western boundary of Glacier National Park on Sept. 16, 2019 near West Glacier, Montana. Chip Somodevilla / Getty Images

By Alex Kirby

New forests are an apparently promising way to tackle global heating: the trees absorb carbon dioxide, the main greenhouse gas from human activities. But there's a snag, because permanently lower river flows can be an unintended consequence.

Read More
Household actions lead to changes in collective behavior and are an essential part of social movements. Pixabay / Pexels

By Greg McDermid, Joule A Bergerson, Sheri Madigan

Hidden among all of the troubling environmental headlines from 2019 — and let's face it, there were plenty — was one encouraging sign: the world is waking up to the reality of climate change.

So now what?

Read More
Sponsored
Logging state in the U.S. is seen representing some of the consequences humans will face in the absence of concrete action to stop deforestation, pollution and the climate crisis. Mark Newman / Lonely Planet Images / Getty Images

Talk is cheap, says the acting executive secretary of the United Nations Convention on Biological Diversity, who begged governments around the world to make sure that 2020 is not another year of conferences and empty promises, but instead is the year to take decisive action to stop the mass extinction of wildlife and the destruction of habitat-sustaining ecosystems, as The Guardian reported.

Read More
The people of Kiribati have been under pressure to relocate due to sea level rise. A young woman wades through the salty sea water that flooded her way home on Sept. 29, 2015. Jonas Gratzer / LightRocket via Getty Images

Refugees fleeing the impending effects of the climate crisis cannot be forced to return home, according to a new decision by the United Nations Human Rights Committee, as CNN reported. The new decision could open up a massive wave of legal claims by displaced people around the world.

Read More
The first day of the Strike WEF march on Davos on Jan. 18, 2020 near Davos, Switzerland. The activists want climate justice and think the WEF is for the world's richest and political elite only. Kristian Buus / In Pictures via Getty Images

By Ashutosh Pandey

Teenage climate activist Greta Thunberg is returning to the Swiss ski resort of Davos for the 2020 World Economic Forum with a strong and clear message: put an end to the fossil fuel "madness."

Read More