Is the northern high-latitude land-based CO2 sink weakening?
Text S1: Details on the updates to model components and process representations related to the simulated fluxes analyzed in this study. (341Kb)
Hayes, Daniel J.
McGuire, A. David
Kicklighter, David W.
Gurney, Kevin R.
Burnside, T. J.
Melillo, Jerry M.
MetadataShow full item record
Studies indicate that, historically, terrestrial ecosystems of the northern high-latitude region may have been responsible for up to 60% of the global net land-based sink for atmospheric CO2. However, these regions have recently experienced remarkable modification of the major driving forces of the carbon cycle, including surface air temperature warming that is significantly greater than the global average and associated increases in the frequency and severity of disturbances. Whether Arctic tundra and boreal forest ecosystems will continue to sequester atmospheric CO2 in the face of these dramatic changes is unknown. Here we show the results of model simulations that estimate a 41 Tg C yr−1 sink in the boreal land regions from 1997 to 2006, which represents a 73% reduction in the strength of the sink estimated for previous decades in the late 20th century. Our results suggest that CO2 uptake by the region in previous decades may not be as strong as previously estimated. The recent decline in sink strength is the combined result of (1) weakening sinks due to warming-induced increases in soil organic matter decomposition and (2) strengthening sources from pyrogenic CO2 emissions as a result of the substantial area of boreal forest burned in wildfires across the region in recent years. Such changes create positive feedbacks to the climate system that accelerate global warming, putting further pressure on emission reductions to achieve atmospheric stabilization targets.
Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 25 (2011): GB3018, doi:10.1029/2010GB003813.
Showing items related by title, author, creator and subject.
Importance of recent shifts in soil thermal dynamics on growing season length, productivity, and carbon sequestration in terrestrial high-latitude ecosystems Euskirchen, E. S.; McGuire, A. David; Kicklighter, David W.; Zhuang, Qianlai; Clein, Joy S.; Dargaville, R. J.; Dye, D. G.; Kimball, John S.; McDonald, Kyle C.; Melillo, Jerry M.; Romanovsky, V. E.; Smith, N. V. (2005-10-07)In terrestrial high-latitude regions, observations indicate recent changes in snow cover, permafrost, and soil freeze-thaw transitions due to climate change. These modifications may result in temporal shifts in the growing ...
Mehta, Amee V.; Allen, Judith M.; Constantine, Rochelle; Garrigue, Claire; Jann, Beatrice; Jenner, Curt; Marx, Marilyn K.; Matkin, Craig O.; Mattila, David K.; Minton, Gianna; Mizroch, Sally A.; Olavarría, Carlos; Robbins, Jooke; Russell, Kirsty G.; Seton, Rosemary E.; Steiger, Gretchen H.; Víkingsson, Gísli A.; Wade, Paul R.; Witteveen, Briana H.; Clapham, Phillip J. (Inter-Research, 2007-10-25)Certain populations of killer whales Orcinus orca feed primarily or exclusively on marine mammals. However, whether or not baleen whales represent an important prey source for killer whales is debatable. A hypothesis by ...
Song, Xiangzhou; Yu, Lisan (American Meteorological Society, 2012-05-15)The study examined global variability of air–sea sensible heat flux (SHF) from 1980 to 2009 and the large-scale atmospheric and ocean circulations that gave rise to this variability. The contribution of high-latitude ...