Nav: Home

A key to climate stabilization could be buried deep in the mud, FSU researchers suggest

September 18, 2018

TALLAHASSEE, Fla. -- Earth's peatland soils store a lot of carbon -- about as much as currently flows freely through the atmosphere as carbon dioxide. As global temperatures rise, scientists worry that the planet's grip on these carbon reservoirs could weaken, unleashing a "carbon bomb" that could further destabilize Earth's climate systems.

But a new study led by Florida State University offers some hope that Earth's carbon reservoirs might not be quite as vulnerable as experts predict. In a global survey of peatlands -- areas defined by soil-like, partially decomposed organic matter -- researchers found signs that these carbon-rich environments could show some level of long-term resilience even as temperatures continue to climb.

"There's a lot of concern about losing these carbon reservoirs, but what this study suggests is that they are more stable than we initially thought," said Jeff Chanton, the Robert O. Lawton Distinguished Professor of Oceanography. "This mutes the carbon bomb hypothesis. It's good news."

The findings were published in the journal Nature Communications.

Peat forms most frequently in the North, where cooler climes prevent organic matter from fully decomposing. But peatlands can also be found in the tropics, where warm weather facilitates rapid decomposition.

This puzzled a team of researchers from FSU's Departments of Chemistry and Biochemistry and Earth, Ocean and Atmospheric Science. If tropical peatlands can successfully withstand equatorial temperatures, they asked, might northern peatlands also have the capacity to stabilize in warmer conditions?

To investigate, the team collected peat samples from a globally representative selection of far-flung sites -- subarctic Swedish mires, temperate North Carolina bogs and tropical Bornean peat swamps to name a few. They then used advanced spectroscopy tools to investigate the unique chemical profiles of their samples.

The team quickly identified significant chemical differences between peat sourced from higher and lower latitudes.

"Peat from warm climates had lower concentrations of carbohydrates and higher concentrations of aromatics compared to peat from colder climates," said former FSU postdoctoral researcher Suzanne Hodgkins, who led the study.

Cold-climate peat, with its higher carbohydrate concentration, is considered by scientists to be more labile, or more easily degradable. As temperatures increase, the carbohydrates in the peat decompose and carbon dioxide is emitted.

Warm-climate peat sampled from lower latitudes, on the other hand, was found to be largely depleted of carbohydrates. Instead, these samples contained high levels of aromatics -- stable chemical compounds left behind by decomposed plant matter.

As temperatures rise at higher latitudes, northern peatlands will burn off their surface store of carbohydrates, releasing carbon dioxide into the atmosphere. The key to what happens next lies in the chemistry of the peat buried deep below the Earth, said Hodgkins, now a postdoctoral researcher at Ohio State University.

"The long-term stability of northern peat in the face of warming depends on whether it can develop a chemistry similar to tropical peats," she said "Initially, northern peat will likely decompose and release carbon into the atmosphere, but eventually this decomposition will reduce the abundance of carbohydrates relative to aromatics. This change in chemistry could stabilize the remaining peat against further decomposition."

If, after the initial carbohydrate burn, northern peatlands come to more closely resemble their southern counterparts -- which have endured in warm weather for millennia -- then their aromatic-dominant chemistry could act as a bulwark against further decomposition and carbon dioxide release.

"Evidence from the study suggests that northern peatlands may develop many of the same compositional features as southern peatlands, mitigating to some extent the potential for substantial carbon losses to the atmosphere," said retired Professor of Analytical and Environmental Chemistry Bill Cooper, who helped direct the study.

This mitigation is contingent on the rate of carbohydrate decomposition and the ways northern plant ecology adapts to warmer temperatures, but it could play a major role in preventing considerable amounts of carbon dioxide from reaching an already-warming atmosphere.

However, while stable peatlands may help avert worst-case scenarios and temper the dreaded carbon bomb, researchers said these kind of ecological restraints on warming are not enough to reverse global climate trends.

"All of these natural processes pale in comparison to the rate at which human beings are releasing fossil fuel CO2 into the atmosphere," Chanton said. "We're releasing CO2 at enormous rates, so this is not going to save us."
-end-
The Duke University Wetland Center played an instrumental role in spearheading this research. The study was funded primarily by the U.S. Department of Energy, with additional funding from the National Science Foundation, the Natural Sciences and Engineering Research Council of Canada, the National Research Foundation Singapore, Geo.X (the Research Network for Geosciences in Berlin and Potsdam, Germany), and the National Aeronautics and Space Administration.

Florida State University

Related Atmosphere Articles:

New study detects ringing of the global atmosphere
A ringing bell vibrates simultaneously at a low-pitched fundamental tone and at many higher-pitched overtones, producing a pleasant musical sound. A recent study, just published in the Journal of the Atmospheric Sciences by scientists at Kyoto University and the University of Hawai'i at Mānoa, shows that the Earth's entire atmosphere vibrates in an analogous manner, in a striking confirmation of theories developed by physicists over the last two centuries.
Estuaries are warming at twice the rate of oceans and atmosphere
A 12-year study of 166 estuaries in south-east Australia shows that the waters of lakes, creeks, rivers and lagoons increased 2.16 degrees in temperature and increased acidity.
What makes Saturn's atmosphere so hot
New analysis of data from NASA's Cassini spacecraft found that electric currents, triggered by interactions between solar winds and charged particles from Saturn's moons, spark the auroras and heat the planet's upper atmosphere.
Galactic cosmic rays affect Titan's atmosphere
Planetary scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) revealed the secrets of the atmosphere of Titan, the largest moon of Saturn.
Physics: An ultrafast glimpse of the photochemistry of the atmosphere
Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.
Using lasers to visualize molecular mysteries in our atmosphere
Molecular interactions between gases and liquids underpin much of our lives, but difficulties in measuring gas-liquid collisions have so far prevented the fundamental exploration of these processes.
The atmosphere of a new ultra hot Jupiter is analyzed
The combination of observations made with the CARMENES spectrograph on the 3.5m telescope at Calar Alto Observatory (Almería), and the HARPS-N spectrograph on the National Galileo Telescope (TNG) at the Roque de los Muchachos Observatory (Garafía, La Palma) has enabled a team from the Instituto de Astrofísica de Canarias (IAC) and from the University of La Laguna (ULL) to reveal new details about this extrasolar planet, which has a surface temperature of around 2000 K.
An exoplanet loses its atmosphere in the form of a tail
A new study, led by scientists from the Instituto de Astrofísica de Canarias (IAC), reveals that the giant exoplanet WASP-69b carries a comet-like tail made up of helium particles escaping from its gravitational field propelled by the ultraviolet radiation of its star.
Iron and titanium in the atmosphere of an exoplanet
Exoplanets can orbit close to their host star. When the host star is much hotter than our sun, then the exoplanet becomes as hot as a star.
Astronomers find exoplanet atmosphere free of clouds
Scientists have detected an exoplanet atmosphere that is free of clouds, marking a pivotal breakthrough in the quest for greater understanding of the planets beyond our solar system.
More Atmosphere News and Atmosphere Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Sound And Silence
Sound surrounds us, from cacophony even to silence. But depending on how we hear, the world can be a different auditory experience for each of us. This hour, TED speakers explore the science of sound. Guests on the show include NPR All Things Considered host Mary Louise Kelly, neuroscientist Jim Hudspeth, writer Rebecca Knill, and sound designer Dallas Taylor.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

Kittens Kick The Giggly Blue Robot All Summer
With the recent passing of Ruth Bader Ginsburg, there's been a lot of debate about how much power the Supreme Court should really have. We think of the Supreme Court justices as all-powerful beings, issuing momentous rulings from on high. But they haven't always been so, you know, supreme. On this episode, we go all the way back to the case that, in a lot of ways, started it all.  Support Radiolab by becoming a member today at Radiolab.org/donate.