Part of our efforts towards curbing the deleterious effects of climate change is the reduction of the very things that our society is putting up into the atmosphere that’s part of the blame for all this: greenhouse gases. These gases, when left to their own devices up in the atmosphere, trap heat that’s coming in from the Sun, thereby accelerating whatever heating occurs down here.
Since the days of discovering just what exactly we’re leaving behind for our descendants with our pollution and waste, we’ve been hard at work cutting off the major sources of these gases: shifting away from gas-powered vehicles, using renewable sources of energy, and other similar attempts.
However, we might not be looking into all places where these gases may come from. Or at the very least, this certainly appears to be the case with new findings published in the journal Nature Communications. There, a team of scientists found a major source for nitrous oxide (N2O), one of the major greenhouse gases—and it may very well lie beneath the feet of some of you right now.
The nitrous oxide the researchers detected appear to be coming from a type of permafrost called Yedoma; Yedoma covers about a million square kilometers (around 386,000 sq. mi.) of land in the Northern Hemisphere, and it is rich in organic material.
In particular, the authors focused on two rivers in Siberia, named the Lena and Kolyma Rivers. These rivers manage to melt the permafrost where the soils make contact with the water near and around its edges; from there, it manages to release about 10 and 100 times as much N2O as we would expect from normal permafrost thaw.
“The high ice content of Yedoma makes it vulnerable for abrupt thaw and ground collapse, allowing rapid mobilization of soil carbon and nitrogen stocks after thaw.” Writing in their published paper, the authors continued: “Along Arctic rivers and the coastal zone of the Arctic Shelf, thawing of Yedoma permafrost creates steep, tens-of-meters-high Yedoma exposures, where many of the conditions known to promote N2O emissions from permafrost-affected soils are met.”
The news comes directly after findings released just a few months prior that detail just how the loss of surface ice on Earth is warping the planet’s surface in ways we had not been able to identify before.
Nitrous oxide coming from the Yedoma in this manner is produced by the microbes locked within the ice-laden soils. At first glance, it appears to have an insignificant effect on atmospheric temperature levels, as N2O is far less abundant compared to greenhouse heavyweights like carbon dioxide (CO2); however, N2O is also about 300 times stronger than CO2 as a “warming agent,” at least when accounting for a recent 100-year period in data.
There also appears to be a balancing act between microbes that produce N2O and those that consume it; as the Yedoma thaws, the side that consumes N2O loses out to those that produce it, leaving the thawing permafrost with a surplus that escapes into the atmosphere.
This comes as a stark contrast to previous findings which found the nitrogen cycling in similarly-cold Arctic soils to be “very slow,” and that most N2O emissions come from agricultural sources.
“The nitrogen release from thawing permafrost can substantially improve the availability of nitrogen in Arctic ecosystems, which, in addition to the direct climatic feedback in the form of nitrous oxide, may have important consequences on carbon fixation by plants and eutrophication of water systems,” says lead author and University of Eastern Finland environmental scientist Maija Marushchak.
Given these findings, the researchers believe there is much work to be done to ascertain the true extent of just how much nitrogen can be found in permafrost across the world—and the work must be done before our planet dives further into this climate crisis and the damage sets in.
(For more news about greenhouse gas emissions, check out how the Amazon Rainforest now releases more carbon that it absorbs.)
References
- Marushchak, M. E., Kerttula, J., Diáková, K., Faguet, A., Gil, J., Grosse, G., Knoblauch, C., Lashchinskiy, N., Martikainen, P. J., Morgenstern, A., Nykamb, M., Ronkainen, J. G., Siljanen, H. M. P., van Delden, L., Voigt, C., Zimov, N., Zimov, S., & Biasi, C. (2021). Thawing Yedoma permafrost is a neglected nitrous oxide source. Nature Communications, 12(1), 7107. https://doi.org/10.1038/s41467-021-27386-2
- Nield, D. (2021, December 12). Scientists find a new source of a greenhouse gas emissions in the siberian permafrost. ScienceAlert. https://www.sciencealert.com/scientists-find-a-new-source-of-a-greenhouse-gas-in-the-siberian-permafrost
- US EPA, O. (2015, December 23). Overview of greenhouse gases [Overviews and Factsheets]. https://www.epa.gov/ghgemissions/overview-greenhouse-gases
