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The statements seem perfectly reasonable with the exception of the word 'sudden'. How quickly must the methane clathrates be release to qualify as sudden? Days, months, years, decades? In the context of the Paleocene–Eocene Thermal Maximum of 55 million years ago, would one thousand years be sudden? I'm going to edit out sudden and remove the tag "This section needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (July 2008)". Please let me know your views on this matter.
--Id447 (talk) 20:02, 20 June 2010 (UTC)[reply]
Here are the updated NOAA Graphs: 2008 Methane Graph (with Slope/Growth Rate). ftp://ftp.cmdl.noaa.gov/ccg/figures/ch4_tr_global.png
2011 Methane Graph (only Mauna Loa) http://www.esrl.noaa.gov/gmd/webdata/ccgg/iadv/graph/mlo/mlo_ch4_ts_obs_03437.png
They don't seem to be providing an updated version of the "Growth Rate" graph. However, both of these graphs clearly show Methane Growth beyond 2005. I'm having troubles updating the image page to reflect new figures without starting a whole new page.Keelec (talk) 12:05, 2 February 2011 (UTC)[reply]
I added an {update} template to the graph because there has been a significant change in methane emissions since 2005, when the current graph ends. The NOAA data is in the public domain. Green Cardamom (talk) 04:26, 14 December 2011 (UTC)[reply]
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An image used in this article, File:MethaneSourcePieChart.jpg, has been nominated for speedy deletion at Wikimedia Commons for the following reason: Copyright violations
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A further notification will be placed when/if the image is deleted. This notification is provided by a Bot, currently under trial --CommonsNotification (talk) 10:43, 6 May 2011 (UTC)[reply] |
See section above #Updated Graphs. (this section a template placeholder). Green Cardamom (talk) 04:39, 14 December 2011 (UTC)[reply]
Methane plus oxygen plus ultraviolet light yields water vapor and carbon monoxide and infrared radiation. Carbon monoxide plus ultraviolet light plus oxygen yields carbon dioxide and infrared radiation. Water vapor is far more efficient as an absorbent of infrared than is carbon dioxide. Additionally, all of the biogenic producers of methane also produce carbon dioxide and water vapor as well as infrared radiation which are all released into the atmosphere. My point? Methane is far more important as a greenhouse gas than carbon dioxide is because it leads to such a large increase in atmospheric water vapor. -- Brothernight (talk) 13:04, 17 December 2011 (UTC)[reply]
Item C. in the list is "Forest fire – Mass burning of organic matter releases huge amounts of methane into the atmosphere." Methane released during forest fires would also burn in the fire (just like in Natural Gas). The Article should be edited to remove the above item C.Ugaap (talk) 02:32, 30 December 2012 (UTC)[reply]
The section on landfills states:
A footnote gives the website uspowerpartners.org as a reference for this statement. The web page linked from the reference does not offer any further information about how they have derived this purported fact, and it is at odds with official government statistics compiled by the EPA, see [1]. According to figures given by the EPA for 2009, landfills in the US emitted 117.5 TgCO2-equiv, which puts them in a distant third place behind “natural gas systems” (221.2 TgCO2-equiv) and “enteric fermentation” (139.8 TgCO2-equiv).
It is possible that someone at Power Partners misinterpreted a sentence in the EPA report which begins: “In the United States, the largest methane emissions come from the decomposition of wastes in landfills ...” but in its entirety reads: “In the United States, the largest methane emissions come from the decomposition of wastes in landfills, ruminant digestion and manure management associated with domestic livestock, natural gas and oil systems, and coal mining.” For some odd reason, EPA has chosen to list contributing factors in more or less reverse order of their significance, with fossil fuel extraction and distribution at the end of the list.
Subject to objections, suggestions, and further discussion of same, I will soon correct the sentence in question to read:
Piperh (talk) 00:09, 8 January 2013 (UTC)[reply]
Methane as a greenhouse gas section: If methane has a half-life of 7 years and it's 20-year greenhouse warming potential is 86, it's "at a given time"-potential can't be anywhere close to 100. It must be about 300 or so. Plus, I would very much like to see a source for the amount of "large effect" on a truly brief period, if the reader like me is interested in a period << 20 years. Thank you very much --2A02:8070:23C1:8D00:1C02:5487:6795:6520 (talk) 15:29, 20 July 2014 (UTC) There is a NASA paper that put it at 104x forcing of CO2(-e) in the atmosphere not considering any timeframe as I understand it. will look for link. I'm not sure the shape of the depletion curve but you would think it would be something like a decay curve. the products of (oxidation for want of a better word) also have a GHG effect. [WideEyedPupil][reply]
Graph shows "current period" at left but is only 280ppm CO2, That's not "current" so what year is actually "at the left"? Raquel Baranow (talk) 06:15, 6 March 2015 (UTC)[reply]
The atmospheric half life of Methane of 7 years references the page at Phys.org. But the Phys.org page, references wikipedia. We have a reference looping problem -- self reference. Blue Tie (talk) 03:53, 22 March 2015 (UTC)[reply]
It's odd to me that the forcing of methane would be listed in 100 year GWP terms given that for 93 of those years more than half of the methane will not be present. Contrary to assertions some people make, 100 year has no basis in science as a gold standard for GWP. It's nearly be chosen as a reference point to discuss GHGs with very warming different potentials and life-spans in the atmosphere relative to an anthropic scale. It would make a lot more sense to use the ten year or twenty year Global Warming Potential of methane when introducing the gas.
Given the IPCC has chosen 20yr and 100yr as reference scales to use with regularity, 20 year lifespan and associated GWP is the logical choice. Using 100 GWP greatly reduces the apparent impact in the next twenty years during which time many climatic tipping points may have been crossed that are, effectively for mankind at this time, irreversible. Please change methane's GWP to 86x CO2-e in the 20 year timescale in the introduction. Or at least state that first and then the 100yr GWP. WideEyedPupil (talk) 04:50, 18 February 2016 (UTC)[reply]
