As the climate warms, wetland bacteria may produce more methane, altering the delicate balance between gas production and consumption. Researchers have identified a trend of increasing methane emissions from wetlands over the last decade.
Wetland bacteria could make more methane in a warming world, as higher temperatures favor the activity of methane-producing microbes at the expense of those that consume it. Researchers have found that warmer temperatures and rising CO2 concentrations may be tipping the scales, shifting the biogeochemistry of wetlands and altering the relative microbial activity.
The balance between methane production and consumption in wetlands is crucial in keeping emissions of the gas from check. However, recent research has identified a worrisome trend: an uptick in wetlands’ emissions of methane over the last decade, with strong spikes in 2013 and again in ‘2020’ . This finding offers clues to how future warmer temperatures might affect microbial activity.
Wetlands are significant sources of methane, a potent greenhouse gas.
These ecosystems produce approximately 25% of global methane emissions.
The majority of wetland methane comes from anaerobic decomposition in saturated soils and sediments.
This process is accelerated by factors like waterlogging, temperature, and microbial activity.
Wetland methane emissions have increased due to climate change, land-use changes, and human activities like agriculture and urbanization.
To test this, researchers conducted a summer field study in coastal wetlands near the Chesapeake Bay, analyzing soil conditions in a set of marshy plots with differing environmental conditions. They found that under warming conditions alone, methane-producing bacteria were able to snag sulfate faster, leaving less for the methane consumers. However, when additional CO2 was added to simulate likely future Earth conditions, the team’s surprise was that it actually counteracted the warming trend somewhat by encouraging the conversion of hydrogen sulfide back to sulfate.
Methane-producing bacteria, also known as methanogens, are microorganisms that produce methane gas as a byproduct of their metabolism.
These microbes thrive in low-oxygen environments and can be found in swamps, marshes, and the digestive systems of ruminant animals.
Methanogens play a crucial role in the carbon cycle, contributing to greenhouse gas emissions and influencing climate change.
They are also used in wastewater treatment and biofuel production.
This study fills in one piece of the puzzle, but as lead researcher Jaehyun Lee noted, ‘you can’t actually predict what’s going to happen until you understand all the little pieces.’ The findings highlight the role that sulfate plays in those emissions and offer valuable clues for better estimating sources and sinks of methane in the future.
The study’s results also have implications for how we might reduce wetland methane emissions. By identifying which types of microbes are more active, researchers may be able to develop strategies to encourage the growth of methane-consuming bacteria.
Methane-consuming bacteria, also known as methanotrophs, are microorganisms that play a crucial role in the Earth's ecosystem.
These bacteria can convert methane into carbon dioxide and water, reducing greenhouse gas emissions.
There are two main types of methanotrophs: type I and type II.
Type I methanotrophs are aerobic, requiring oxygen to thrive, while type II methanotrophs are facultative anaerobes, able to survive in low-oxygen environments.
Methane-consuming bacteria have been found in various ecosystems, including soil, water, and even the human gut.
- sciencenews.org | Wetland bacteria could make more methane in a warming world
