Video and poster - methane in the Arctic

Methane in the Arctic threatens to escalate into runaway global warming.

The poster shown in the video is added below. 

Click on the poster to view a higher-resolution version, for printing out and hanging it on the wall.

Methane in the Arctic

Methane is often said to have a Global Warming Potential (GWP) of 21 times as strong as carbon dioxide, a figure based on IPCC assessment reports that date back to the 1990s. However, the IPCC has updated methane's GWP several times since, as illustrated in Table 1. below.

In its Fourth Assessment Report (AR4, 2007), the IPCC gives methane a GWP of 25 as much as carbon dioxide over 100 years and 72 as much as carbon dioxide over 20 years.

Furthermore, a 2009 study, by Drew Shindell et al., points out that the IPCC figures do not include direct+indirect radiative effects of aerosol responses to methane releases that increase methane's GWP to 105 over 20 years when included

Moreover, in the context of tipping points, which seems appropriate regarding methane releases in the Arctic, it makes sense to focus on a short time horizon, possibly as short as a few years.

Accordingly, methane's GWP can best be visualized as in the image below, which is also displayed mid-right on the poster above.

The image on the left shows methane's global warming potential (GWP) for different time horizons, pointing out that methane's GWP is more than 130 times that of carbon dioxide over a period of ten years.

IPCC¹ figures were used to create the blue line. The red line is based on figures in a study by Shindell et al.², which are higher as they include more effects. This study concludes that methane's GWP would likely be further increased by including ecosystem responses.

The ecosystem response can be particularly strong in the Arctic, where the seabed contains huge amounts of methane. Continued warming in the Arctic can cause large abrupt methane releases which in turn can trigger further methane releases from sediments under the sea.

This is particularly worrying, not only because of the presence of huge amounts of methane, but also because the sea is quite shallow in areas such as the East Siberian Arctic Shelf (ESAS), which in the case of large abrupt releases can soon lead to oxygen depletion in the water and make that much of the methane will enter the atmosphere without being oxidized in the water.

Additionally, low water temperatures and long sea currents in the Arctic Ocean are not very friendly toward bacteria that might otherwise break down methane in the water.

For further background, also see the post The potential impact of large abrupt release of methane in the Arctic at the Arctic Methane blog³, and the FAQ page at that blog.

References:

1. IPCC, Climate Change 2007: Working Group I: The Physical Science Basis, Table 2.14 (2007)
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-10-2.html

2. D.T. Shindell et al., "Improved Attribution of Climate Forcing to Emissions". Science vol 326: pp. 716-718 (2009)
http://www.sciencemag.org/content/326/5953/716.abstract

3. Sam Carana, The potential impact of large abrupt release of methane in the Arctic (2012)
http://arcticmethane.blogspot.com/2012/05/potential-impact-of-large-abrupt.html

Striking increase of methane in the Arctic

Click on image to enlarge

Dr. Leonid Yurganov, Senior Research Scientist, JCET, UMBC, and member of AMEG, produced the above images with IASI/METOP satellite data (EUMETSAT).

The images show methane levels for 2008, 1-10 November, and for 2011, 1-10 November.

The images show a striking increase of methane over the shelf areas of the Arctic Ocean.

For reference, the image on the right is added, showing predicted methane hydrates, as published by WWF with surface temperature hotspots added.

Dr. Yurganov points at the threat of large emissions of methane from clathrates (methane hydrates) in the Arctic, and urges others to support his proposals for further satellite methane monitoring.

Current growth of methane is being monitored by the Atmospheric Infrared Sounder (AIRS) facility on NASA's Aqua satellite.

Dr. Yurganov has been using AIRS data for years and points at an image he produced using AIRS data. The image shows that, during the autumn of 2011, the anomaly in the Northern Hemisphere was substantially larger than the anomaly in the Southern Hemisphere.
ftp://asl.umbc.edu/pub/yurganov/methane/AIRS_CH4_2002-2012.pdf

Monthly mean maps of methane are available at Dr. Yurganov's website. The maps have been produced using AIRS data since 2002 up to now, for both the Northern Hemisphere and the Southern Hemisphere. The maps are at:
ftp://asl.umbc.edu/pub/yurganov/methane/MAPS/

Comparisons with other instruments for the Arctic are still few or lacking. Examples are for TANSO, May-November, 2010:
ftp://asl.umbc.edu/pub/yurganov/methane/MAPS/TANSO_2010day&night.jpg

Arctic - red alert!

Temperature rise projections

The Climate Emergency Institute recently produced the image below. For more background, see the institute's page on the warming that Earth's is already committed to even if people's emissions were suddenly stopped. Also see the institute's warning on Food Security.