<
https://e360.yale.edu/digest/thawing-permafrost-in-sweden-releases-less-methane-than-feared-study-finds>
"A study in northern Sweden found that melting permafrost released one tenth as
much methane as expected, suggesting emissions from thawing Arctic tundra could
be less than previously feared.
Once Arctic permafrost melts, microbes are able to consume the once-frozen
organic matter trapped in the soil. As a byproduct of this process, microbes
produce large amounts of methane, an extremely potent greenhouse gas.
Scientists have long warned that rising temperatures would spur the release of
more methane in the Arctic, leading to yet further warming. But new research on
melting permafrost in Sweden suggests such emissions may be much smaller than
predicted.
For the study, scientists gauged emissions from one swath of permafrost that
thawed in the 1980s and another that thawed 10 to 15 years later. Emissions in
the first area were 10 times less than in the second. That’s because as ice
melted underground in the first area, water on the surface began to sink down
into the soil. As the surface dried out, new plants emerged that helped keep
methane emissions buried underground.
Grasses typical of wet areas have straw-like systems that convey oxygen to
their roots and also allow methane in the soil to escape into the atmosphere.
As those areas grow dry, grasses are replaced with dwarf shrubs, willows, and
birch, which lack such systems.
“When methane can no longer escape through the straws, soil bacteria have more
time to break it down and convert it into CO2,” said Bo Elberling, director of
the Center for Permafrost at the University of Copenhagen and co-author of the
study. That CO2, which is also a greenhouse gas, appears to stay in the ground,
scientists observed. The findings were published in the journal
Global Change
Biology."
Via Reasons to be Cheerful
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
