Emissions of Key Greenhouse Gas Stabilize

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."

Comments

That's not as much help as you might think.

[sbaker]

The thing is that it takes lots of years for the effect of gas ratio changes at sea level to propagate up into the upper atmosphere.

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.

Re:Arctic

[DigitalRaptor]

I don't know enough about which ice is over the ocean and which is over land, but much of it is over land.

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.

IIRC it's one of the greatest potential contributors to the "tipping point".

Re:Arctic

[alexhard]

Let me guess....you just pulled that out of your ass didn't you?

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

Re:Arctic

[alexhard]

damn, forgot to link..
http://www.gsfc.nasa.gov/topstory/20020820 southseaice.html

Re:CO2

[toolazytothink]

But in fact, human behaviour does not seem to be changing water vapour concentrations in the atmosphere, while as many many scientists have observed, rising concentrations of CO2 (which seem to be linked to rising levels of development, and energy production and use) are proportional to temperature increases. Water is a much more complicated greenhouse gas because it goes into the atmosphere easily, but it also comes out easily. CO2, on the other hand does not leave the atmosphere easily, and it is having a measurable effect on our climate.

Re:I wonder if this has to do with BSE

[Qzukk]

They're not a major source of methane in the atmosphere OR their crap puts off a ton of methane and we should use it as fuel?

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 claims that livestock causes 15 of all organic-sourced methane "emissions". Mostly due to fermentation in their stomachs, mostly from low quality feed.