Quantcast

Global Warming Speeds Up Methane Emissions From Freshwater

Climate

British scientists have identified yet another twist to the threat of global warming. Any further rises in temperature are likely to accelerate the release of methane from rivers, lakes, deltas, bogs, swamps, marshlands and rice paddy fields.

Most of the methane in freshwater systems is produced by an important group of microbes called
Archaea that live in waterlogged, oxygen-free sediments. Photo courtesy of Shutterstock

Methane or natural gas is a greenhouse gas. Weight for weight, it is more than 20 times more potent than carbon dioxide (CO2) over a century, and researchers have repeatedly examined the contribution of natural gas emitted by ruminant cattle to global warming. But Gabriel Yvon-Durocher of the University of Exeter and colleagues considered something wider: the pattern of response to temperature in those natural ecosystems that are home to microbes that release methane.

They report in Nature that they looked at data from hundreds of field surveys and laboratory experiments to explore the speed at which the flow of methane increased with temperature.

Microbes, algae, freshwater plants and animals are all part of an active ecosystem and take their nourishment from and return waste to the atmosphere. Healthy plants take CO2 from the atmosphere with photosynthesis. Most of the methane in freshwater systems is produced by an important group of microbes called Archaea that live in waterlogged, oxygen-free sediments and play an important role in decay.

Plant uptake of CO2 is affected by temperature, and so is microbial methane production. Respiration also releases CO2. The questions the researchers set out to answer were: which gas is more likely to be released in greater quantities as temperatures rise? And is the outcome the same whether they examine the Archaea only, or all the microbes in an ecosystem, or the entire package of submerged freshwater life?

More Heat, More Methane

The answer is, the scientists say, that methane emissions go up with the mercury, and that the ratio of methane to CO2 also goes up in step with temperature. And the result is the same whether you consider the microbes or the whole ecosystem.

“The discovery that methane fluxes are much more responsive to temperature than the processes that produce and consume carbon dioxide highlights another mechanism by which the global carbon cycle may serve to accelerate rather than mitigate future climate change,” said Dr. Yvon-Durocher.

This is not the end of the story. All such studies raise as many questions as they answer, and more research is necessary. The next puzzle is how to fit such findings into models of climate change. However, the researchers feel they have cleared up one point. Dr. Yvon-Durocher said:

“Our research provides scientists with an important clue about the mechanisms that may control the response of methane emissions from ecosystems to global warming.”

Visit EcoWatch’s CLIMATE CHANGE page for more related news on this topic.

 

EcoWatch Daily Newsletter

A verdant and productive urban garden in Havana. Susanne Bollinger / Wikimedia Commons

By Paul Brown

When countries run short of food, they need to find solutions fast, and one answer can be urban farming.

Read More Show Less
Trevor Noah appears on set during a taping of "The Daily Show with Trevor Noah" in New York on Nov. 26, 2018. The Daily Show With Trevor Noah / YouTube screenshot

By Lakshmi Magon

This year, three studies showed that humor is useful for engaging the public about climate change. The studies, published in The Journal of Science Communication, Comedy Studies and Science Communication, added to the growing wave of scientists, entertainers and politicians who agree.

Read More Show Less
Sponsored
rhodesj / Flickr / CC BY 2.0

Cities around the country are considering following the lead of Berkeley, California, which became the first city to ban the installation of natural gas lines in new homes this summer.

Read More Show Less
Rebecca Burgess came up with the idea of a fibersheds project to develop an eco-friendly, locally sourced wardrobe. Nicolás Boullosa / CC BY 2.0

By Tara Lohan

If I were to open my refrigerator, the origins of most of the food wouldn't be too much of a mystery — the milk, cheese and produce all come from relatively nearby farms. I can tell from the labels on other packaged goods if they're fair trade, non-GMO or organic.

Read More Show Less
A television crew reports on Hurricane Dorian while waves crash against the Banana River sea wall. Paul Hennessy / SOPA Images / LightRocket / Getty Images

By Mark Hertsgaard and Kyle Pope

Some good news, for a change, about climate change: When hundreds of newsrooms focus their attention on the climate crisis, all at the same time, the public conversation about the problem gets better: more prominent, more informative, more urgent.

Read More Show Less
Sponsored
U.S. Senators Chris Coons (D-Del.) and Mike Braun (R-Ind.) met with Bill Gates on Nov. 7 to discuss climate change and ways to address the challenge. Senator Chris Coons

The U.S. Senate's bipartisan climate caucus started with just two members, a Republican from Indiana and a Democrat from Delaware. Now it's up to eight members after two Democrats, one Independent and three more Republicans joined the caucus last week, as The Hill reported.

Read More Show Less
EPA scientists survey aquatic life in Newport, Oregon. U.S. Environmental Protection Agency

The U.S. Environmental Protection Agency (EPA) is proposing to significantly limit the use of science in agency rulemaking around public health, the The New York Times reports.

Read More Show Less
A timelapse video shows synthetic material and baby fish collected from a plankton sample from a surface slick taken off Hawaii's coast. Honolulu Star-Advertiser / YouTube screenshot

A team of researchers led by the National Oceanic and Atmospheric Administration didn't intend to study plastic pollution when they towed a tiny mesh net through the waters off Hawaii's West Coast. Instead, they wanted to learn more about the habits of larval fish.

Read More Show Less