The Ups and Downs of Methane

Posted: July 17, 2013 by tallbloke in alarmism, Carbon cycle, general circulation, Natural Variation, Ocean dynamics, paleo

A new paper on Methane is out which is fanning the dying embers of climate catastrophism:

 

It’s worth reading this Reblog from worldclimatereport.com for some context

One of the indisputable facts in the field of global climate change is that the atmospheric build-up of methane (CH4) has been, over the past few decades, occurring much more slowly than all predictions as to its behavior (Figure 1). Since methane is a particularly potent greenhouse gas (thought to have about 25 times the warming power of CO2), emissions scenarios which fail to track methane will struggle to well-replicate the total climate forcing, likely erring on the high side—and feeding too much forcing into climate models leads to too much global warming coming out of them.

methane09_fig1
Figure 1. Atmospheric methane concentrations, 1985-2008, with the IPCC methane projections overlaid (adapted from: Dlugokencky et al., 2009)

Figure 2 shows the year-over-year change in the methane concentration of the atmosphere, and indicates not only that the growth rate of methane has been declining, but also that on several occasions during the past decade or so, it has dropped to very near zero (or even below) indicating that no increase in the atmospheric methane concentration (or a even a slight decline) occurred from one year to the next.

methane09_fig2
Figure 2. Year-to-year change in atmospheric methane concentrations, 1985-2008, (source: Dlugokencky et al., 2009)

This behavior is quite perplexing. And while we are not sure what processes are behind it, we do know one thing for certain—the slow growth of methane concentrations is an extremely cold bucket of water dumped on the overheated claims that global warming is leading to a thawing of the Arctic permafrost and the release of untold mega-quantities of methane (which, of course, will lead to more warming, more thawing, more methane, etc., and, of course, to runaway catastrophe).

To some, the blip upwards in methane growth in 2007 (Figure 2) was a sure sign that the methane beast was awakening from its unexpected slumber. Climate disaster was just around the corner (just ask Joe Romm).

But alas, despite the hue and cry, in 2008 the increase in methane, instead of equaling or exceeding the 2007 rise, turned out to be only about half of the 2007 rise. And together with information on from where it seemed to emanate (the tropics rather than the Arctic), it cannot be taken as a sign that the slow methane growth rate during the past decade was coming to an end as a result of an Arctic meltdown.

Here is how NOAA methane-guru Ed Dlugokencky and colleagues put it in their publication last week describing recent methane behavior:

We emphasize that, although changing climate has the potential to dramatically increase CH4 emissions from huge stores of carbon in permafrost and from Arctic hydrates, our observations are not consistent with sustained changes there yet.

The factual portion of their conclusion remains the same, with or without the inclusion of the final word (but it sure was nice of them to throw it in there as a bone to climate catastrophists the world over).

Reference

Dlugokencky, E. J., et al., 2009. Observational constraints on recent increases in the atmospheric CH4 burden. Geophysical Research Letters36, L18803, doi:10.1029/2009GL039780.

Comments
  1. Roger, Please read my post http://cementafriend.wordpress.com/2011/10/14/methane-good-or-bad/
    An engineer such as yourself should know that reaction kinetic is an engineering subject (chemical engineering) which it seems ordinary scientists and especially the followers of that pseudo science “climate science” do not understand.
    Turn on the burner dial of your LPG barbecue or those who have natural gas stoves in their home. What happens? Gas escapes but no burning (ie oxidation) until you light it. LPG and methane require an ignition temperature. Your car has a spark plug for the petrol/air mixture. A car running on LPG also has to have a spark plug. More than that the mixture has to be heated because the ignition temperature is higher than petrol.
    Next you have to think about the ratio of gas and air Those who have done a bit of soldering using a nozzle supplied by bottled LPG will know if you have the gas too high the flame will blow off and go out. If you use a big nozzle with lots of air holes and you turn down the gas the flame will go out because there is not enough gas in the mixture.
    In the atmosphere methane will not burn because it a)it is too low temperature and b) there is insufficient gas to support combustion.
    Now have a look at the absorption spectrum and compare CO2 and methane or find data on emissivity (as in a table in chap 5 of Perry’s Chemical Engineering Handbook).. Methane absorbs or emits only a small fraction of radiation compared to CO2.(less than one fifth) which in turn is a very small fraction of water vapor.
    The supposed effect of methane is a green inspired “beat-up” which some oil and gas companies approve because they want to sell gas instead of coal.

  2. michael hart says:

    As you suggest, Dlugokencky appears to be struggling to marry catastrophist theory with the facts of the never arriving disaster.

    Thus in the title of the reference atmospheric CH4 is a “burden”

    From the abstract: “Near-zero CH4 growth in the Arctic during 2008 suggests we have not yet activated strong climate feedbacks from permafrost and CH4 hydrates.”-Once more, disaster isn’t happening but they are still confident in their assumptions of dreaded feedbacks.

    Another confidently alarmist Dlugokencky title: “Global atmospheric methane: budget, changes and dangers.” http://rsta.royalsocietypublishing.org/content/369/1943/2058.full
    Published by the Royal Society, the abstract has some modestly outrageous claims regarding CO2 reduction and carbon trading.

    I strongly doubt that the carbon isotope ratio of methanogenesis, never mind the sources, is any better constrained than that of the oxidised part of the carbon cycle. Probably much worse. They don’t know, but are at least a little bit more honest that they don’t know (probably because the uncertainties are so much larger!)

    Huge, sporadic, oceanic methane-hydrate belches are postulated as sources of atmospheric methane. Maybe they do already occur, but have they actually been observed and quantified? Japan is proposing to mine methane hydrates. Well done Japan.

  3. michael hart says:

    Coincidentally, WUWT has just posted an article about a Nature paper and methane hydrates:
    http://wattsupwiththat.com/2013/07/16/nature-puts-methane-hydrate-fears-to-rest-says-it-will-be-1000-years-before-they-make-any-impact/

  4. tchannon says:

    This is a joke?

    Look at figure 1, needs more than a magnifying glass, a microscope more like it. Add in the omitted zero. The thing is a flat line.

    Look at figure 2, look at the scale.