Methane in Siberian Permafrost contributing to Climate Change

In recent years global warming has become a well known influence on the global climate. Carbon dioxide (CO2) is the best-known greenhouse gas. Another, potentially more damaging and dangerous, one is methane (carbon tetrahydride; CH4). Most of it is stored in permafrost soil, and is mainly present in Alaska (United States of America) and Siberia (Russian Federation). This blogpost will focus on the emission of methane in permafrost areas in Siberia and how it affects Russia.

Siberia is a region in the Russia Federation, covering almost 77 percent of its territory from the Ural Mountains to the Pacific Ocean. Siberia is home to about 40 million people, which is only 27 percent of the Russian population.

The term ‘permafrost’ is used to describe ground, including soil and rock, which remains at or below freezing point (0°C) for at least two continuous years (Harris et al.). This does not necessarily mean it is frozen. Nearly 24% of the exposed land area in the Northern Hemisphere is underlain by permafrost (Zhang et al., 1999).

Large amounts of methane are stored in permafrost in the Arctic region (Osudar et al., 2016), and Siberian thaw lakes are part of this. In its natural state methane is not only found below permafrost soil, but also below the sea floor (Khalil, 1999). Soil in Siberia contains about ten to thirty times more carbon than non-permafrost mineral soil (Zimov, Schuur & Chapin, 2006). When it finds its way to the surface and into the atmosphere, it is known as atmospheric methane (Khalil, 1999) and this has increased by 150% since 1750 (IPCC, 2001).
Global warming models predict climatic change will be the largest and most significant in the Arctic and might already be in progress (Lachenbruch & Marshall, 1986). It is unknown at what scale northern Siberian thaw lakes emit methane. This is due to the fact that it is released through spatial bubbling*, which is variable (Walter et al., 2006). The variability in emission of atmospheric methane causes it to be an uncertainty to the atmospheric methane budget, which limits the precision of climate change projections (Wille et al., 2008).

Permafrost soil contains about 900 gigaton (Gt) of carbon content, which exceeds that present in both the atmosphere and the biosphere. Those contain 730 Gt and 650 Gt respectivally (Zimov, Schuur & Chapin, 2006). Considering the global warming potential of methane, the CH4 emission turned the Siberian tundra into an effective greenhouse gas source (Wille et al., 2008). Due to climate change, Siberian thaw lakes continue to expand and thus are a large and increasing source of atmospheric methane (Walter et al., 2006).

In the past two years, multiple media have reported about craters appearing in Siberia. The first account of such was in the summer of 2014 on the Yamal Peninsula (Staufenberg,, 2016). An explanation for these craters is that the increase in global temperature caused permafrost to melt and this, combined with a high enough pressure, can cause the methane present in the soil to explode. Some of these explosions have been close to natural gas extraction fields, which can have disastrous consequences when such an explosion occurs there (Kramer, 2016). All this is yet another warning sign for human induced climate change.

Not only is increased methane emission from Siberian thaw lakes disastrous for the global climate, it is also extremely dangerous to people when these explosions occur and these craters are created. There are no known solutions to try and fix either problems. It might be possible to do damage control by reducing greenhouse gas emission as far aa humanly possible, but is very unlikely.
* This video is helpful to visualise spatial bubbling: https://youtu.be/06Xc3LtZRWo

References
Harris, S. A., French, H. M., Heginbottom, J. A., Johnston, G. H., Ladanyi, B., Sego, D. C.,& Van Everdingen, R. O. (1998). Glossary of Permafrost and Related Ground-Ice Terms. Ottawa, Ontario, Canada: National Research Council of Canada.
Intergovernmental Panel on Climate Change (IPCC) (2001). Technical summary. United Nations Environment Programme. Retrieved on 13 November 2016, from: http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/wg1/017.htm
Khalil, M. A. K. (1999). Non-CO2 Greenhouse Gases in the Atmosphere. Annual Review of Energy and the Environment, 24: 645-661.
Kramer, S. (2016, 24 March). Giant holes found in Siberia could be signs of a ticking climate ‘time bomb’. Business Insider. Retrieved on 13 November 2016, from: uk.businessinsider.com/russian-exploding-methane-craters-global-warming-2016-3?r=US&IR=T
Lachenbruch, A. H., & Marshall, B. V. (1986). Changing Climate: Geothermal Evidence from Permafrost in the Alaskan Arctic. Science, 234(4777): 689-696.
Osudar, R., Liebner, S., Alawi, M., Yang, S. Z., Bussmann, I., & Wagner, D. (2016). Methane turnover and methanotrophic communities in arctic aquatic ecosystems of the Lena Delta, Northeast Siberia. Fems Microbiology Ecology, 92(8).
Staufenberg, J. (2016, 24 July). Methane gas trapped underground in Siberia causes earth’s surface to wobble. Independent. Retrieved on 13 November 2016, retrieved from: http://www.independent.co.uk/news/science/gas-siberia-underground-earth-bounce-climate-change-siberia-global-warming-a7153486.html
Walter, K. M., Zimov, S. A., Chanton, J. P., Verbyla, D., & Chapin, F. S. (2006). Methane bubbling frim Siberian thaw lakes as a positive feedback to climate warming. Nature, 443:71-75.
Wille, C., Kutzbach, L., Sachs, T., Wagner, D., & Pfeiffer, E. M. (2008). Methane emission from Siberian arctic polygonal tundra: eddy covariance measurements and modeling. Global Change Biology, 14(6): 1395-1408.
Zhang, T., Barry, R. G., Knowles, K., Heginbottom, J. A., & Brown, J. (1999). Statistics and characteristics of permafrost and ground-ice distribution in the Northern hemisphere. Polar Geography, 23: 132–154.
Zimov, S. A., Schuur, E. A. G., & Chapin, F. S. (2006). Permafrost and the Global Carbon Budget. Science, 312(5780): 1612-1613.

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