Tag Archives: permafrost

Permafrost, carbon and thermokarsts: the Arctic importance

by Caitlin Douglas

The Arctic covers 5% of the total land mass of the earth and reaches across every longitude: it is important. It is estimated that 1.4 times more carbon is stored in permafrost than is currently circulating in the atmosphere, and there is 1.5 times more carbon in permafrost than is currently being stored in all the earth’s vegetation. William Bowden (2010) outlines this in a Geography Compass article, and explains the relationships between permafrost, thermokarsts and climate change.

Permafrost is soil or rock which remains below 0oC for at least 2-3 years at a time. When permafrost thaws it loses its internal structure and subsides unevenly, and the resulting formation is called thermokarst. The transition from permafrost to thermokarst has important hydrological, geomorphological, biogeochemical and ecological importance to arctic landscapes. Globally, this transition may also release the stored carbon which, due to microbial processes, may be released as carbon dioxide or methane.

In April, a special edition on climate change was published by the journal, Philosophical Transactions of the Royal Society. It outlined key research questions required to better understand the impact of greenhouse gases on climate change. The arctic was prominently featured, and in particular the concern over permafrost melt and potential methane release. Scientists seem to agree that research is needed to understand the transitional process from permafrost to thermokarsts and the possible implications on the global climate.

Bowden, W. 2010. Climate Change in the Arctic – Permafrost, Thermokarst, and Why They Matter to the Non-Arctic World. Geography Compass, 4(10): 1553-1566

Scientists call for climate change early-warning system. The Guardian.  April 18th 2011.

An insight into the consequences of climate change?

Arctic sea iceMethane is a potent greenhouse gas. Human activities, e.g. farming, have resulted in the release of large amounts of methane into the atmosphere. However, in locations across the world, large amounts of methane and carbon are stored in soil or the sea bed. These are released gradually as a natural process.

In a Geography Compass paper, William Bowden raises concerns over this process as Arctic ice and permafrost (frozen ground) begin to thaw in response to climate change. Bowden suggests that stored methane and carbon may be released into the atmosphere, further contributing to the volume of greenhouse gases.

Switching our attention to the Gulf of Mexico, last April’s Deepwater Horizon oil leak also caused the release of a large quantity of methane. Research discovered that methane-absorbing bacteria multiplied rapidly in response. As a result, much of the additional methane was not released into the atmosphere.

The Arctic and Gulf of Mexico may behave very differently from each other. However, research into the Deepwater Horizon oil leak offers an insight into the potential consequences of much greater environmental change.

BBC News (6th January 2011) ‘Gulf of Mexico oil leak may give Arctic climate clues’.

Bowden, William B. (2010) ‘Climate Change in the Arctic – Permafrost, Thermokarst, and Why They Matter to the Non-Arctic World’. Geography Compass 3 (10): 1553-1566