A Note: Global Warming Threads

[arfa brane]

If you want to find some actual evidence that Methane is INCREASING then post it.
Otherwise, CH4 continues to be LESS and LESS of a percent of the GHG forcing.

"The abundance of methane in the Earth's atmosphere in 1998 was 1745 parts per billion (ppb), up from 700 ppb in 1750. By 2008, however, global methane levels, which had stayed mostly flat since 1998, had risen to 1,800 ppb.[6]

By 2010, methane levels, at least in the Arctic, were measured at 1850 ppb, a level scientists described as being higher than at any time in the previous 400,000 years.[7] Historically, methane concentrations in the world's atmosphere have ranged between 300 and 400 ppb during glacial periods commonly known as ice ages, and between 600 to 700 ppb during the warm interglacial periods.

In addition, there is a large (but unknown) amount of methane in methane clathrates in the ocean floors. The Earth's crust contains huge amounts of methane. Large amounts of methane are produced anaerobically by methanogenesis. Other sources include mud volcanoes, which are connected with deep geological faults; landfill; and livestock (primarily ruminants) from enteric fermentation."

--http://en.wikipedia.org/wiki/Methane

So let's see what the article says: methane concentration has increased from 1745 ppb in 1998, to 1850 ppb in 2010, that's an increase of 105 ppb in 22 years, following an increase of 1045 ppb over ~ 250 years.

[Billy T]

It's a HOT SPRING Billy, the water below it is BOILING, it is NOT methane gas.

But it IS scary (if it was in fact methane gas) and that's why you posted it.

Arthur

No, I am only quoting others, including NSF, about methane "bursting" into the atmosphere. All I have ever said is that in recent years CH4 has been "bubbling up" fast enough to enter the atmosphere, instead of dissolve as a gas in the ocean water before it reaches the surface. - Much more modest than "bursting up" as the photo is trying to illustrate.

Why is it you only want to comment on a photos origin instead of address the NSF's and Science article's claims that this is the most serious positive feedback systems in the atmospheric carbon system*, not yet even considered in the IPCC's models etc. etc.?

* later by edit: their exact words were: “the most dangerous amplifying feedback in the entire carbon cycle.”

BTW, I JUST RECHECKED: the caption under the photo claiming it is methane only appears at this source: http://www.thinkglobalgreen.org/METHANE.html and not at the other source I also gave.

[occidental]

.

But it IS scary (if it was in fact methane gas)...
Arthur

http://www.youtube.com/watch?v=eM5WPl69Z18

This video shows a large plume of methane-rich gas continuously bubbling in a tundra lake in Alaska. In the background is a rubber raft used by researchers to explore field sites and collect data. Katey Walter Anthony made this recording in the summer of 2007.

Scary.

[adoucette]

BS

Talk about GULLIBLE.

Apparently if it is on YOU TUBE your little brain just accepts that it is the truth....

That's a friggin DIVER underwater.

The bubbles are MOVING and indeed, move past the friggin anchored boat.

LOL

Get a life.

Arthur

Oh, I forgot, hi little Buddy.

[adoucette]

"The abundance of methane in the Earth's atmosphere in 1998 was 1745 parts per billion (ppb), up from 700 ppb in 1750. By 2008, however, global methane levels, which had stayed mostly flat since 1998, had risen to 1,800 ppb.[6]

By 2010, methane levels, at least in the Arctic, were measured at 1850 ppb, a level scientists described as being higher than at any time in the previous 400,000 years.[7] Historically, methane concentrations in the world's atmosphere have ranged between 300 and 400 ppb during glacial periods commonly known as ice ages, and between 600 to 700 ppb during the warm interglacial periods.

In addition, there is a large (but unknown) amount of methane in methane clathrates in the ocean floors. The Earth's crust contains huge amounts of methane. Large amounts of methane are produced anaerobically by methanogenesis. Other sources include mud volcanoes, which are connected with deep geological faults; landfill; and livestock (primarily ruminants) from enteric fermentation."

--http://en.wikipedia.org/wiki/Methane

So let's see what the article says: methane concentration has increased from 1745 ppb in 1998, to 1850 ppb in 2010, that's an increase of 105 ppb in 22 years, following an increase of 1045 ppb over ~ 250 years.

Ah, don't compare GLOBAL levels, as you were doing, to the LAST figure, which was just the Arctic.

Apples to Apples.

And YES, CH4 has increased ONE PART PER MILLION over 22 years.

So, NO, the sky is not falling (at least because of atmospheric CH4).

LOL

Arthur

[arfa brane]

Ah, don't compare GLOBAL levels, as you were doing, to the LAST figure, which was just the Arctic.

Why does the figure of 1850 ppb for the Arctic, NOT compare with a global level?

Surely there is a global level of atmospheric methane (it's a "well-mixed" gas, right?) and it can be compared with the figure for the Arctic??

You asked for evidence of increases in methane; the evidence is that tundra continues to melt and humans continue to produce GHGs. This could be because humans are confident about their ability to predict the effects of increasing CO2 on the release of stored methane, or it could be because humans don't really care about next century.

[adoucette]

Why does the figure of 1850 ppb for the Arctic, NOT compare with a global level?

Surely there is a global level of atmospheric methane (it's a "well-mixed" gas, right?) and it can be compared with the figure for the Arctic??

You asked for evidence of increases in methane; the evidence is that tundra continues to melt and humans continue to produce GHGs. This could be because humans are confident about their ability to predict the effects of increasing CO2 on the release of stored methane, or it could be because humans don't really care about next century.

The REAL reason is because we have a lot of friggin cows and we grow a lot of rice and we drill for a lot of Oil/Natural gas.



You can't use readings from one area because Methane varies quite a bit based on seasons and latitude.

Which is why we have a published Global value which is NOT the same as the local values (which vary quite a bit based on, well local conditions).

Arthur

[occidental]

BS

Talk about GULLIBLE.

Apparently if it is on YOU TUBE your little brain just accepts that it is the truth....

That's a friggin DIVER underwater.

The bubbles are MOVING and indeed, move past the friggin anchored boat.

LOL

Get a life.

Arthur

Oh, I forgot, hi little Buddy.

Wrong.

Its from a documentary that clearly shows its methane.

LOL indeed.

[arfa brane]

You can't use readings from one area because Methane varies quite a bit based on seasons and latitude.

Which is why we have a published Global value which is NOT the same as the local values (which vary quite a bit based on, well local conditions).

Of course you can "use" readings from one area, you can compare the readings to a global value.

If the values in one area are increasing, then the global value must be increasing. This fact has nothing to do with the effect of the increase.

Methane levels are stabilised by hydroxyl production, so as long as the latter exceeds the production (release) of the former it should remain stable.

This is known to be a temporary situation because it's also a fact that at least twice in the earth's zoological history methane concentrations have been high enough to cause mass extinctions. One of these occured at the end of the Permian and wiped out 95% of ocean dwelling species--the oceans became stagnant and didn't recover for tens of thousands of years.

[adoucette]

Based on your say so I'm going to believe you?

Not a chance.

The bubbles are moving and there aren't those kind of currents in a friggin lake.

Like I said, gullible.

Arthur

[adoucette]

This is known to be a temporary situation because it's also a fact that at least twice in the earth's zoological history methane concentrations have been high enough to cause mass extinctions. One of these occured at the end of the Permian and wiped out 95% of ocean dwelling species--the oceans became stagnant and didn't recover for tens of thousands of years.

One of many conjectures for the extinction event.

Arthur

[adoucette]

Of course you can "use" readings from one area, you can compare the readings to a global value.

If the values in one area are increasing, then the global value must be increasing. This fact has nothing to do with the effect of the increase.

They didn't say it was increasing in the Arctic though, did they?

One POINT does not a SLOPE make.

Macehead Ireland, also a Northern one of our monitoring sites, is routinely 100 ppb over the global average (that site was reporting in the middle 1900's last year).

Arthur

[arfa brane]

They didn't say it was increasing in the Arctic though, did they?

They didn't say it was decreasing or staying the same either.

The question: is global methane increasing year on year, appears to have an answer which is "yes". This is despite local variability, as in Macehead, or the Arctic. Because the increase is globally "small" the rate of increase has a small slope. It can't be zero unless all the methane released is then destroyed. This cannot be the case or methane concentration would be about 700 ppm, as it was about 250 years ago.

So we have that in the last 22 years, a global increase of ~100 ppm methane has been recorded. The global level is limited by hydroxyl production. So how many ppm methane is required to overcome this limitation, or how much is enough to swamp the hydroxyl and leave a net "undamped" concentration? Will this scenario lead to uncontrolled warming and flip the climate "out" of the current glacial period, and for how long? Is this possible by increasing CO2 levels alone?

I guess we'll all just have to wait and see--that's more or less what we're doing, and none of us will be able to wait long enough to see what "will" happen (because we don't live long enough), so we don't care.

[adoucette]

They didn't say it was decreasing or staying the same either.

The question: is global methane increasing year on year, appears to have an answer which is "yes". This is despite local variability, as in Macehead, or the Arctic. Because the increase is globally "small" the rate of increase has a small slope. It can't be zero unless all the methane released is then destroyed. This cannot be the case or methane concentration would be about 700 ppm, as it was about 250 years ago.

So we have that in the last 22 years, a global increase of ~100 ppm methane has been recorded. The global level is limited by hydroxyl production. So how many ppm methane is required to overcome this limitation, or how much is enough to swamp the hydroxyl and leave a net "undamped" concentration? Will this scenario lead to uncontrolled warming and flip the climate "out" of the current glacial period, and for how long? Is this possible by increasing CO2 levels alone?

NO

Parts Per BILLION not PPM.

CO2 goes up about 2 parts per MILLION per year, but the increase over the last 22 years for Methane has been 100 PARTS PER BILLION, which is essentially FLAT.

Arthur

[arfa brane]

Ok, sorry I got carried away and posted ppm instead of ppb, which makes the rate of increase look unscarily "flat".

But it isn't flat, it's got a slope. It's also looking flat because hydroxyl is being produced, which is the main limiting factor.

So how big does the rate of methane production need to be before the hydroxyl production is swamped? Is this a scenario that "can never happen"?

Wait, let me guess, because I posted ppm INSTEAD of ppb, now I don't have a leg to stand on. You can use my mistake to assert that you're the only person here who knows what they're talking about.

[adoucette]

It's got a nearly flat slope.

And no, it's not only removed via hydroxyl production, there are multiple methods and as we learned from the BP oil spill, there is ample global capacity to remove CH4.

http://geosciences.tamu.edu/hotlinks...gulf-of-mexico

Arthur

[arfa brane]

And no, it's not only removed via hydroxyl production, there are multiple methods and as we learned from the BP oil spill, there is ample global capacity to remove CH4.

So hydroxyl production rate isn't the main limiter of atmospheric methane, then?

How much methane is enough to swamp the hydroxyl and leave a net "undamped" concentration? Will this just be removed by "other" mechanisms?

[adoucette]

So hydroxyl production rate isn't the main limiter of atmospheric methane, then?

Yes I believe it is:

The recent decline in growth rates implies that emissions now approximately match removals, which are due primarily to oxidation by the hydroxyl radical (OH).
Since the TAR, new studies using two independent tracers (methyl chloroform and 14CO) suggest no significant long-term change in the global abundance of OH. Thus, the slowdown in the atmospheric CH4 growth rate since about 1993 is likely due to the atmosphere approaching an equilibrium during a period of near-constant total emissions ”

IPCC AR4 WG1 Technical Summary - TS.2.1.1 Changes in Atmospheric Carbon Dioxide, Methane and Nitrous Oxide

How much methane is enough to swamp the hydroxyl and leave a net "undamped" concentration? Will this just be removed by "other" mechanisms?

Hard to say, what we do know is that in the BP spill

Nature quickly saw to the removal of more than 200,000 metric tons of dissolved methane through the action of bacterial blooms that completely consumed the immense gas plumes that the team had identified in mid-June.

So I'd say, that while hydroxyl is probably the main "scubber" of methane, clearly the globe has OTHER methods for fairly rapidly dealing with massive quantities of Methane as well.

Arthur

[arfa brane]

The gulf oil spill occured in water. Methane in the atmosphere is a much less accessible source of energy for bacteria.

What is the likely timescale for bacteria to remove an excess of methane from the atmosphere, after it swamps hydroxyl production?
Say the concentration changes abruptly from ~1800 to around 18000 ppb because of a large release from clathrate decomposition?

Would the removal be rapid enough that global temperatures stayed fairly constant?
Does the IPCC consider this scenario is possible, or is it discounted, or in the "we don't know" basket?

[occidental]

Based on your say so I'm going to believe you?

Not a chance.

The bubbles are moving and there aren't those kind of currents in a friggin lake.

Like I said, gullible.

Arthur

The video and description is from the University of Alaska Fairbanks College of Engineering and Mines. What basis do you have to claim theyre lying?