2017-04-06. High Arctic Emissions of a Strong Greenhouse Gas.

posted Apr 8, 2017, 7:58 AM by Alan Gould
By Sarah Stanley, Earth & Space News, AGU, Global Biogeochemical Cycles. For GSS Climate Change chapter 3 and Ozone chapter 2. Excerpt: Nitrous oxide, often called “laughing gas,” is perhaps most famous for its use as an anesthetic. However, it is also a powerful greenhouse gas that harms the ozone layer; in fact, nitrous oxide contributes more to ozone depletion than any other component of human emissions. But there are many natural sources of the gas as well. In a new study, Gil et al. explore the isotopic composition and potential sources of nitrous oxide emitted by soils in the subarctic tundra. ...About 60% of the nitrous oxide found in the atmosphere escapes from the soils of farms and tropical forests. Until recently, scientists assumed that nitrous oxide emission was negligible in colder climates. Then, in 2009, researchers discovered that bare areas of peat in frozen tundra soils emit the odorless gas at rates similar to those of tropical forests. ...Different microbial processes leave distinct isotopic fingerprints on nitrous oxide; thus, they hoped to figure out the relative amounts of nitrous oxide emitted by different nitrogen-processing microbes in the tundra. ...high tundra emissions might be due to nitrifier denitrification, in which microbes transform ammonia into dinitrogen (N2) in a series of steps, one of which produces nitrous oxide. ...the data were inconclusive, and their technique did not provide enough information to tease out the relative roles of different microbes. ...enhanced emissions from subartic tundra might cancel out mitigation actions at lower latitudes. Therefore, a rich set of isotopic nitrous oxide data from around the world could help scientists pinpoint regions that serve as emission sources as climate change progresses. (Global Biogeochemical Cycles, https://doi.org/10.1002/2015GB005370, 2017)...  https://eos.org/research-spotlights/high-arctic-emissions-of-a-strong-greenhouse-gas