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Emissions of Key Greenhouse Gas Stabilize
Posted by
samzenpus
on Wed Nov 22, 2006 07:32 PM
from the barter-town-halts-production dept.
from the barter-town-halts-production dept.
brian0918 writes "Multiple news sites are reporting that levels of the second most important greenhouse gas, methane, have stabilized". From Scientific American: "During the two decades of measurements, methane underwent double-digit growth as a constituent of our atmosphere, rising from 1,520 parts per billion by volume (ppbv) in 1978 to 1,767 ppbv in 1998. But the most recent measurements have revealed that methane levels are barely rising anymore — and it is unclear why." From NewScientist: "Although this is good news, it does not mean that methane levels will not rise again, and that carbon dioxide remains the 800-pound gorilla of climate change."
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Water Vapor? (Score:5, Interesting)
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I meant that when you are considering the sun it's effects on the oceans and the irrigation areas constant.
"AGAIN you couldn't be more wrong. evaporation has nothing to with with depth, and everything to do with SURFACE AREA, of which the ocean clearly dwarfs our irrigation."
It has to with the temprature. Shallow waters heat up
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That's because it's complete bollocks. You have it backwards: volcanoes produce a tiny fraction of the greenhouse gases humans cause to be emitted. Feel free to try to find a source for your "facts".
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Well, I guess it was good while it lasted!
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The atmospheric lifetime of carbon dioxide is difficult to define because it is exchanged with reservoirs having a wide range of turnover times; IPCC 2001, (page 38 [grida.no]) gives a range of 5-200 years.
The lifetime of excess atmospheric carbon dioxide [agu.org] (Global Biogeochemical Cycles - American Geophysical Union)
If one assumes a terrestrial biosphere with a fertilization flux, then our best estimate is that the single half-life for excess CO2 lies within the range of 19 to 49 years
Arctic (Score:5, Insightful)
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Re:Arctic (Score:5, Insightful)
The ice that is there may come and go (freeze and thaw) with the seasons, but it is indisputable that there is a hell of a lot more going than there is coming back.
Satellite imagery from the 70's to now is shocking and disappointing, even bordering on the scary (beyond scary, I think).
Parent
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Let me reference nasa.gov:
"While recent studies have shown that on the whole Arctic sea ice has decreased since the late 1970s, satellite records of sea ice around Antarctica reveal an overall increase in the southern hemisphere ice over the same period."
Get your stories straight or don't post..misinformation doesn't benefit anyone
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http://www.gsfc.nasa.gov/topstory/2002082
Re:Arctic (Score:5, Interesting)
Not sure what your point is here since the GP didn't mention Anatartica, Arctic ice comes from the Arctic (north), Antartic ice comes from Antartica (south). Since the mid 1950's the Arctic ice cap has lost ~60% of it's volume (although one "skeptic" belives the missing ice is hiding behind Canada somewhere).
There has been very little change in the volume of the Antartic ice cap, however both the Antartic penninsula and Greenland have experinced a +3C rise in average tempratures compared to the +1C global average (accurately predicted by climate models I might add).
Parent
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If the predictions are right then this is the calm before the storm. If the Arctic melts, which it is, it'll release vast amounts of methane.
Uh, perhaps this is a naive question, but the frozen Arctic is, well, ice. Where is the carbon going to come from to make CH4? Now, there are probably some levels of CO2 trapped in ice bubbles, but speaking naively I don't see how this is a hugely significant contribution to global atmospheric carbon levels?
Not that a thawed Arctic wouldn't suck for other reaso
Re:Arctic (Score:5, Informative)
Much of that land is comprised of old peat bogs and other partially decomposed plant life.
As it is exposed and thaws it releases huge amounts of methane. This has already been observed and written about at length [google.com].
IIRC it's one of the greatest potential contributors to the "tipping point [google.com]".
Parent
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It is suprising that methane has stabilized. There was a paper published this summer stating that melting permafrost was releasing methane at a much higher rate than expected. This would mean that some other source of methane would have to be slowing. If this is true it is good news indeed. Methane is a far more potent greenhouse gas than
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And that is also incorrect (Score:3, Informative)
Sources of methane (Score:4, Funny)
Does the stabilization of methane levels mean they're now feeding beano to cattle?
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Just in case bozos out there actually believe it: The IPCC estimates that 60% of methane produced comes from our agriculture, industry, and waste. Humans are the biggest single source of methane. In North America and Europe, the largest single source of methane comes from landfills. The largest source of natural methane comes from wetlands.
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This would be funnier if it weren't partially true. Australian farmers have been experimenting with a "vaccine" that stimulates the immune systems of cows to kill some of the natural microbes in their digestive tracts -- the ones responsible for releasing much of the methane. Given that they're messing with cows' biology in this way, I sure hope it doesn't turn out that cow-methane isn't the problem we think it is.
Burping, not farting (Score:2)
Lots of methane comes from anaerobic activity (rotting vegetation/sawdust, landfills, waste water processing etc). Even atural swamps and forest floor decomposition produce a lot of methane and CO2.
Methane is far worse than CO2, thus it is preferable to burn off methane than let is escape into the atmosphere. Better still to bu
Obligatory (Score:2, Informative)
I'll bet global methane emissions can be shown to track the gross sales of Taco Bell.
Hmmmm... their stock has climbed steadily since August [nasdaq.com]. Perhaps the methane readings are due to their recent switch to Canola oil [marketwatch.com].
That's not as much help as you might think. (Score:4, Informative)
From the vague article, these appear to be sea-level measurements - so the density of methane in the upper atmosphere (where it actually matters) will continue to grow for maybe 10 years before it starts to level off.
We are seeing the effects of methane growth rates in the 1980's and 1990's...it'll get worse before it gets better.
Let me get this straight (Score:5, Funny)
The methane gas was coming from an 800-pound gorilla?
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The methane gas was coming from an 800-pound gorilla?
Gentlemen, I have our solution.
We wait till wintertime rolls around... the 800lb gorillas simply freeze to death!
American beer (Score:3, Funny)
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The chief cause of beer flatulence is yeast cells. The second biggest cause is complex sugar. It is something that your bowel can adjust to over time, so people who regularly drink beer with yeast in it aren't so affected by it. Ironically, the American swill beer you mention is filtered and pasteurized, so it contains no yeast at all. And anybody who's tasted a Coors Light can also tell you that the complex sugar content is practically nonexistent. So, American megaswill should be among the LEAST likely be
Scares the bejesus out of me (Score:4, Interesting)
Now, out of the blue, something *utterly* unexpected, inexplicable and major happens - the rate of methane emission levels out; and no one has a *CLUE* why.
Well, I can hear this ticking noise...
I sure hope we figure out interplanetry colonization soon.
You know - just in case.
Natural gas prices and methane leaks (Score:3, Interesting)
Natural gas production [pnl.gov] is the leading source of Russian methane emissions, for instance. And in 1990, Russia leaked as much as 26 million tons of methane. It was probably worth their while to plug some of these leaks at current prices.
Re:Wait a minute... (Score:5, Funny)
Parent
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<sarcasm>Actually, no. Our knowledge is complete. Visit the Creationism Museum to learn more.</sarcasm>
Fixed that for you...
Re:Wait a minute... (Score:5, Funny)
Parent
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Sarcasm aside I do worry what would happen if some one put it into the minds of the fundy Christians that Global Warming was the precursor to revelations and the like. With their collective political power in the first world I think we'd have a huge problem on our hands just like we do with their infection of the common understanding of science among the
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Using their patties for biofuel is something I think North Americans aren't looking at closely enough. There's definately fosssil-type fuel to be had from their back end production.
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I believe it is the latter. They are a significant contributor to the methane problem AND we should be harnessing every bit of methane we can as fuel.
For the record, cows produce a lot of methane from both ends. Their 4 stomachs and digestion produce a fair amount from that end, and we've all smelt the other ends productio
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Re:I wonder if this has to do with BSE (Score:5, Informative)
Or their crap has no methane and yet can still be used for fuel (your dichotomy is false).
Anyway, http://www.ciesin.org/TG/AG/liverear.html [ciesin.org] claims that livestock causes 15 of all organic-sourced methane "emissions". Mostly due to fermentation in their stomachs, mostly from low quality feed.
Parent
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Termites 11%
Oceans 8%
Hydrates 5%
http://www.epa.gov/methane/sources.html#natural [epa.gov]
So my first guess would be a global reduction of wetlands. Nope, I shall not look for evidence now, it is 3a.m. .
CC.
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"Scientists have discovered why atmospheric levels of methane have stabilised in recent years, but their findings are bad news for industry and agriculture where rising emissions of the greenhouse gas have been revealed.
The scientists, including researchers from France's Climate and Environment Science Laboratory and Australia's national science agency CSIRO, found that a reduction in natural emissions of methane from wetlands has been maskin
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Why has this been hidden by the mods?
This is a valid point, there
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Anyone who disputes climate change is a moron. The debate isn't about whether climate change occurs (of course it does). It's about who caused it.
I don't care which side of the debate you're on -- at least understand what is being debated.
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Unless, of course, the problem wasn't serious enough to warrent attention in the first place, as many environmental skeptics have been saying all along.
Re:CO2 (Score:4, Informative)
Parent
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Last I heard, the oceans covered 2/3rd of the surface of the Earth. It should be pretty clear that, in contrast, evaporation through irrigation on arable land (a fraction of the remaining 1/3) will be a drop in the bucket.
The same can't be said for the production of CO2 from combustion of fossil fuels versus organic processes. And I have never seen spontaneous precipitation of l
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Weather forecasts are pretty accurate. And th
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I am 54 years old. 44 years ago, I remeber walking home from midnight mass in a blizzard. This was in NY City, and garbage trucks had to pile snow and the end of the streets since there was no where to plow it all. We had snow mountains for a month or so. All of this is anecdotal, and certainly not a "geological" time period.
And yet, I have noticed changes which seem to be born out by hard data that something is happening over a period of 29 years, namely that in certain key areas, such as Alaska in t [noaa.gov]
Re:20yrs is not a geological timeframe (Score:4, Insightful)
There is, of course, a vast difference between predicting weather - which is a local phenomena, with significant specificity - and predicting the climate trends - which is averaging general trends globally. Consider, for instance, that it is very hard to stand on a beach and predict the exact height and shape of the next wave and precisely where and when it will break. On the other hand predicting the approximate height and time of the next high tide is rather easier. GCMs are, indeed, currently rather poor at making predictions down to the level of day to day local weather. They have, however, been very accurate [realclimate.org] at predicting year on year global climate.
As noted above, contrary to your claim, the models have proved to be remarkably robust and accurate. They are also, contrary to popular perception in some circles, not just a big pattern matching machine that are "trained" on past data. They are models that are fed in physics. Yes, there are some tweakable parameters, as there should be in any model where there is some uncertainty. The greatest area of uncertainty in models currently is clouds, since they can be both a positive or negative feedback depending on the exact nature of their formation. Of course this problem is taken very seriously and there is a lot of study. The last IPCC report had considerable detail summarising that work [grida.no]. The simple reality, however, is that the models have worked pretty well, and have, in fact, made significant predictions that have since been observed [grist.org].
Historical temperatures from ice-cores are determined by ratios of hydrogen or oxygen isotopes in the ice. The guts of the issue is that when combined in water the different isotopes, being different masses, fractionate out at slightly different temperatures, thus the exact isotope ratio is a function of many things, but a very signficant factor is the prevailing temperature at the time the water became vapout before precipitting out. Thus the ratio, while not an exact indication of specific temperatures (unless the many other factors are also accounted for), is a good indicator of general temperature trends over long time scales. For more detail see here [wileywater.com]. The result is that, using ice cores, we can plot temperature and carbon dioxide independently [wikipedia.org].
Furthermore, more recent temperature reconstructions (as in reconstructions of only the past 1000 years or so) rely not on ice cores but on a wide variety of sources including coral, tree rings, glaciers, and more. Usually many of these different methods are cross referenced with each other to create any single reconstruction. The results can be seen in this plot [wikipedia.org] of 10 different reconstructions by different independent teams. The results, as you can see, while different, all show the same trend. If you're still uncertain, feel free to use the
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