Monday, February 4, 2013

Overview of IASI methane levels

Dr. Leonid Yurganov kindly shared an overview of his analysis of IASI methane levels over the years.
The overview shows a marked difference between methane levels in the Arctic and methane levels at lower altitudes, i.e. between 40 and 50 degrees North. Furthermore, the overview shows a steady increase in methane levels over the years, both at high latitudes and at lower latitudes. Over the Arctic, mean levels of well over 1900 ppb are now common.

The overview gives the mean values for methane levels. Peaks can be much higher. Levels of up to 2241 ppb were registered above the Arctic at 742 mb on January 23, 2013 (see earlier post). Moreover, high levels are registered over a wide area, particularly over the Barents Sea and the Norwegian Sea, which are currently free of sea ice (see earlier post), indicating worrying releases of methane from the seabed in that area.

How much extra methane is released to account for this rise in methane levels? Dr. Yurganov explains: “this may be a relatively slow process, 7 ppb per month for the area between Norway and Svalbard means only 0.3 Tg per month. But in a longer time scale (at least several years) and inclusion of the autumn Kara/Laptev emissions it might be very important both for the methane cycle and for the climate. Further discussion promises to be fruitful”.

Dr. Yurganov plans to update his overview on completion of further analysis of existing data of IASI methane levels for earlier periods, and complemented with further periods in future as the data come along.

Meanwhile, we'll keep a close eye on methane levels in the Arctic, particularly given the prospect that large areas of the Arctic Ocean (Kara Sea, Laptev Sea and East Siberian Sea) will soon become free of sea ice. Further people analyzing methane levels are invited to also comment on the situation in the Arctic.


  1. The non linear nature of change taking place in Arctic is glossed over by simply observing rate of increase of January methane levels in Barents Sea, Norwegian Sea area as if .3petagrams of CH4 were involved. That approx .3metatonnes, methane
    compared to Earth's approx 5gigatonnes atmosphere load at present isn't the issue, it's that change is happening faster and faster and methane level shouldn't have gone up in January. There is approx 1700 billion tonnes of CH4 in offshore continental shelf area of East Siberian Arctic Shelf alone and it is largely beginning to show serious evidence of melting free and getting to sky more and more when the area is ice free. Ice loss in summer is rising exponentially and Earth's ability to shelter
    and provide habitat for life is so declining..
    That Methane, the gov wants to save money by eliminating surface measurement that is used to calibrate satellite measurement. But it's not just that, it's about the disconnect between economics and Earth's commons.
    There is a deliberate attempt to belittle whole situation and disabling the common man to speak.

    1. Good points, Dale, a relatively small change in temperature or an earthquake can destabilize large amounts of methane held in sediments in the Arctic seabed. Years ago, Shakhova et al. considered release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time. As you say, there's currently some 5 Gt of methane in the atmosphere, so that would add ten times that amount, causing an amount of warming in the Arctic that would trigger even further releases.

    2. National Snow and Ice Data Center, News consistently uses evaluations based on extent of sea ice cover not volume of ice comparisons. This makes broken slush on water count same as ice 5meters thick. It hides how quick melt will likely occur come Arctic Spring and then advance..
      The reason for ice not forming in Barents Sea is given as warm current of sea water coming in without mention of increased Methane levels at large. By not mentioning Arctic Sea ice volume levels and Methane increases the public is shielded from understanding what's up and coming soon but because of the urgency of the moment in which action could still happen what can be said here so our President can protect. Make a dramatic appeal to world in his State of temperature Speech coming up in about a week.. Corporations are not people, money is not speech. But our ability to think and speak will weaken soon.