How much methane is located in the Arctic?

Arctic sources of carbon have been studied by a team of researchers at Lawrence Livermore National Laboratory, Livermore, California, United States, led by Joshuah Stolaroff. Their estimates are illustrated in the image below, showing the potential total release, next to their characteristic annual release of methane and the geographic extent for each source.

Stolaroff et al., 2012, DOI: 10.1021/es204686w 

Note: Numbers in brackets behind the figures in above table relate to references below. If you cannot view these references, click here. 


For comparison, the NOAA image below shows the world’s carbon dioxide emissions for each year in PgC (i.e. GtC or billions of tonnes of carbon).

Annual total emissions. The bars in this figure represent carbon dioxide emissions for each year in PgC yr-1 from the specified region. The final bar, labeled ‘Mean’, represents the 2001-2010 average. CarbonTracker models four types of surface-to-amosphere exchange of CO2, each of which is shown in a different color: fossil fuel emissions (tan), terrestrial biosphere flux excluding fires (green), direct emissions from fires (red), and air-sea gas exchange (blue). Negative emissions indicate that the flux removes CO2 from the atmosphere, and such sinks have bars that extend below zero. The net surface exchange, computed as the sum of these four components, is shown as a thick black line. 

Clearly, if merely a fraction of the sources at the top would end up in the atmosphere, we’d be in big trouble. Some of the carbon may be released gradually in the form of carbon dioxide, but it’s much worse if large amounts of methane escape abruptly into the atmosphere, given factors such as methane’s high Global Warming Potential. Anyway, it should be clear that the huge size of some of these sources poses a terrifying threat.  

References

1. Boucher, O.; Folberth, G. A. New Directions: Atmospheric methane removal as a way to mitigate climate change? Atmospheric Environment 2010, 44, 3343 – 3345.
2. Solomon, S. et al. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change; Cambridge University Press: Cambridge, UK, 2007.
   http://www.ipcc.ch/publications_and_data/publications_ipcc_fourth_assessment_report_wg1_report_the_physical_science_basis.htm
3. Reagan, T. M.; Moridis, J. G.; Elliot, M. S.; Maltrud, M.; Cameron-Smith, P. Basin-scale assessment of gas hydrate dissociation in response to climate change. Proceedings of the 7th International Conference on Gas Hydrates (ICGH 2011), 2011.
   http://adsabs.harvard.edu/abs/2010AGUFMOS43B..08R 
4. Mahmoudkhani, M.; Heidel, K.; Ferreira, J.; Keith, D.; Cherry, R. Low energy packed tower and caustic recovery for direct capture of CO2 from air. Energy Procedia 2009, 1, 1535.
5. Heidel, K.; Holmes, G.; Singh, A.; D. Keith, D. Process Costing of A Contactor for Air Capture. 10th International Conference on Greenhouse Gas Control Technologies, Amsterdam, 2010.
   http://keith.seas.harvard.edu/Misc/Process simulation of direct CO2 capture from air.pdf
6. Stolaroff, J. K.; Keith, D. W.; Lowry, G. V. Carbon Dioxide Capture from Atmospheric Air Using Sodium Hydroxide Spray. Environmental Science & Technology 2008, 42, 2728–2735, PMID: 18497115.
   http://pubs.acs.org/doi/abs/10.1021/es702607w
7. Trenberth, K. E.; Smith, L. The Mass of the Atmosphere: A Constraint on Global Analyses. J. Climate 2005, 18, 864–875.
   http://journals.ametsoc.org/doi/abs/10.1175/JCLI-3299.1
8. Seinfeld, J. H.; Pandis, S. N. Atmospheric Chemistry and Physics; John Wiley and Sons: New York, 1998.
9. Massman, W. J. A review of the molecular diffusivities of H2O, CO2, CH4, CO, O3, SO2, NH3, N2O, NO, and NO2 in air, O2 and N2 near STP. Atmospheric Environment 1998, 32, 1111–1127.
10. Maslin, M.; Owen, M.; Betts, R.; Day, S.; Dunkley Jones, T.; Ridgwell, A. Gas hydrates: past and future geohazard? Philosophical Transactions of the Royal Society a-Mathematical Physical and Engineering Sciences 2010, 368, 2369–2393.
    http://rsta.royalsocietypublishing.org/content/368/1919/2369.abstract 
11. Shakhova, N.; Semiletov, I.; Leifer, I.; Salyuk, A.; Rekant, P.; Kosmach, D. Geochemical and geophysical evidence of methane release over the East Siberian Arctic Shelf. Journal of Geophysical Research-Oceans 2010, 115, C08007.
    http://www.agu.org/pubs/crossref/2010/2009JC005602.shtml
12. Shakhova, N.; Semiletov, I.; Panteleev, G. The distribution of methane on the Siberian Arctic shelves: Implications for the marine methane cycle. Geophysical Research Letters 2005, 32, L09601.
    http://www.agu.org/pubs/crossref/2005/2005GL022751.shtml
13. Shakhova, N. E.; Sergienko, V. I.; Semiletov, I. P. The contribution of the East Siberian shelf to the modern methane cycle. Herald of the Russian Academy of Sciences 2009, 79, 237–246.
    http://www.springerlink.com/content/3mx32n6n5w4033w8/
14. Zimov, S. A.; Schuur, E. A. G.; Chapin III, F. S. Permafrost and the Global Carbon Budget. Science 2006, 312, 1612–1613.
    http://www.sciencemag.org/content/312/5780/1612.summary
15. Anisimov, O. A. Potential feedback of thawing permafrost to the global climate system through methane emission. Environmental Research Letters 2007, 2, 045016. http://iopscience.iop.org/1748-9326/2/4/045016 
16. Repo, M. E.; Huttunen, J. T.; Naumov, A. V.; Chichulin, A. V.; Lapshina, E. D.; Bleuten, W.; Martikainen, P. J. Release of CO2 and CH4 from small wetland lakes in western Siberia. Tellus Series B-Chemical and Physical Meteorology 2007, 59, 788–796.
    http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0889.2007.00301.x/abstract
17. Walter, K. M.; Smith, L. C.; Chapin, F. S. Methane bubbling from northern lakes: present and future contributions to the global methane budget. Philosophical Transactions of the Royal Society A 2007, 365, 1657–1676.
    http://rsta.royalsocietypublishing.org/content/365/1856/1657
18. MacDonald, G. M.; Beilman, D. W.; Kremenetski, K. V.; Sheng, Y.; Smith, L. C.;
    Velichko, A. A. Rapid early development of circumarctic peatlands and atmospheric CH(4) and CO(2) variations. Science 2006, 314, 285–288.
    http://www.sciencemag.org/content/314/5797/285.short