Cyprus-Forum.com

[devil]

I've added a new essay on this subject with a discussion forum

[mountainman]

Excellent essay devil, it reminded me of my days as a student.

I was wondering though, how does the annual quantity of methane emissions from cows etc. compare to the annual quantity of methane dischaged to atmosphere by the production of LNG.

[devil]

Thanks!

I have figures on your question but they date from 1995 (source Tetlow-Smith). I give the mean estimated values in teragrams (gx10^12=millions of tonnes) of methane.
Releases
Natural wetlands 115
Rice paddies 110
Enteric fermentation 80
Natural gas exploitation 45
Biomass burning 40
Termites 40
Landfills 40

Since this was published, natural gas production has almost doubled, so my guestimation today would be at least 80, possibly more because the USA then was hardly importing any but, today, is importing nearly 20% of their consumption through LNG with inherently greater losses from the wellhead to the burner.

The enteric fermentation factor is not just cattle but all ruminants. The greatest contribution comes from the Great Plains of Africa with everything from Thompson Gazelles, via Gnus, Cape Buffaloes, Giraffes etc. to Elephants. It is impossible to estimate with any accuracy the emissions. It is probable that the greatest individual producer is the hippo but the proportions produced in the gut and by the disturbance of silt is, AFAIK, unknown. There are >1 billion domesticated ruminants of various sizes from sheep upwards. Those that graze produce more methane than those fed on cattle feed which is more digestible for the animals and are thus consumed in smaller quantities than grass.

My best guess is that, today, NG and animal sources are about equal, give or take an ounce or two. However, there is a difference: at least half of the NG produced by animals is from wild animals and has been always emitted, thus forming part of the background level (pre-industrial 800 ppbv). All the NG is from man-made sources, thus contributing to the increase to the present-day concentration of ~1,800 ppbv. Thus, well over half of the methane in the atmosphere is derived from human activities (rice culture being the most important, contributing to ~20% of the total emissions alone).

[Shipwreck]

Who gets paid to figure out these wonderful snippets of info that are of no interest to the common folks???

[Eliko]

devil, any idea as to how much is produced by our politicians ?.

[devil]

Who gets paid to figure out these wonderful snippets of info that are of no interest to the common folks???

Ah, but it is. If you have no water because it doesn't rain as a result of climate change, then you say it is of no interest?

Note that I'm not saying that the drought is a result of climate change, but it may be.

[devil]

devil, any idea as to how much is produced by our politicians ?.

Far too much, because the emissions from their mouths are worse than their farts

[Reg]

I note there is no discussion on the use of LPG for automotive use in the essay, mixed LPgas is available now in Cyprus, it is ideal for propulsion being a clean fuel, with low CO Sulphur and Nox. I have used Auto LPG in the UK starting back in the 70's. At present I believe it it is illegal to use LPG as a road fuel in Cy.