Comments on: Are We Measuring Methane Accurately in Calculating GHG Emissions?

By: lenrosen4

Thu, 15 May 2014 14:07:15 +0000

In reply to lenrosen4.

The study which provided the data on trace gas contributions versus CO2 is by Daniel Lashof and Dilip Ahuja, entitled “Relative contributions of greenhouse gas emissions to global warming.” It appeared in “Letters to Nature,” Volume 344, pages 529-531 on April 5, 1990.

An explanation on radiative forces – MIT News back in March 2010 provided a terrific explanation in a two-part series on greenhouse gases and climate change. You can read the entry at http://newsoffice.mit.edu/2010/explained-radforce-0309.

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By: lenrosen4

Thu, 15 May 2014 14:02:41 +0000

In reply to Enjuneer.

From a study published in Nature in 1990 the authors proposed an index of global warming potential for methane, carbon monoxide, nitrous oxide, CFCs and CO2. Methane was described has having a global warming potential per mole, 3.7 times that of CO2. The research indicated that in the period of the study from 1980 to 1990 these gases were responsible for 43% of increased radiative force within the atmosphere but were present in concentrations 2 to 6 orders of magnitude less than CO2. So methane, carbon monoxide, nitrous oxide, and CFCs are stronger absorbers of infrared radiation than CO2 even though the latter is the major contributor to global warming at a ratio of 4:1 – CO2 to trace gases. In 1990 that amounted to 57% of the increased radiative forces in the atmosphere during the 1980s. Of course, since this study CO2 concentrations have increased from 340 ppm to 400 ppm. I don’t have the numbers for increases in methane from industrial activity and permafrost melt for the same period but in any case methane oxidizes in about a decade so its impact is more transient than permanent.

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By: Enjuneer

Wed, 14 May 2014 17:02:05 +0000

How is green house gas strength or if you will “Activity” measured? Specifically, just a very few years ago, what appeared to be the accepted oft-published green house gas “activity” relative to CO2 was 5 times more active. Then, just in this past year, I have seen this relative number rapidly rise from 5 to 20 to 50 times as “active” as CO2. At least one very recent publication that purports to know how much more active of a GHG than CO2 estimates it at a factor of 34. Now folks, this is a HUGE difference in relative GHG strength to CO2 and will have a great impact on what ever calculations one makes with it. So what is CH4’s relative GHG strength to CO2? Is it 5, 20, 34 or 50? I’ve searched the internet for an answer as to how GHG “activity” is measured and what the real number is and I can’t find a thing. Are those who write the articles and in the media, for lack of something better, just choosing a number that they like and best supports their “position” on climate change?

Here we are, poised to completely take down the United States middle class livelihood using information and numbers that is so divergent, that the largess of have to be completely wrong.

Come on American media, if we can’t do better than the obvious junk put out on methane’s GHG activity, how in the world can we think we have anywhere near the correct scientifically objective conclusions?

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