Jump to content
  • Member Statistics

    17,610
    Total Members
    7,904
    Most Online
    NH8550
    Newest Member
    NH8550
    Joined

Vergent
 Share

Recommended Posts

Perhaps this has been touched on earlier in this thread, but does anyone know what's caused the slowdown in methane rises from 2000-Present?

1750+ CH4 is pretty rare in the paleoclimate record. I would surmise that environmental forcings were simply "maxed" out in the 2000's. Looks like we have accelerated slightly in the last few years and especially in 2013. A more appropriate question to ask is if the recent Methane jump is a "glitch" or a real trend.

 

Interesting that the methane trend appears to have followed the rate of global temperature rise.

Link to comment
Share on other sites

1750+ CH4 is pretty rare in the paleoclimate record. I would surmise that environmental forcings were simply "maxed" out in the 2000's. Looks like we have accelerated slightly in the last few years and especially in 2013. A more appropriate question to ask is if the recent Methane jump is a "glitch" or a real trend.

Interesting that the methane trend appears to have followed the rate of global temperature rise.

Perhaps methane is the key to the puzzle and not co2.

Link to comment
Share on other sites

Perhaps this has been touched on earlier in this thread, but does anyone know what's caused the slowdown in methane rises from 2000-Present?

It is interesting. There is actually a downward trend from 1999 till 2005.

Link to comment
Share on other sites

I believe the downturn then flattening of CH4 is usually ascribed to the chaotic period following the breakup of the Soviet Union.

 

Whether CH4 levels are following or driving global temperature rise might make an interesting subject by itself.

 

Howard predicates his argument on the concept that at ~ 2C runaway feedbacks occur causing additional warming. Hansen and colleges see the danger at +1.8C with S&S even lower.

 

If CH4 pushes us to one of these tipping points in 10 years or 20 years the 100 year GWP of CH4 obviously isn't of concern.

The IPCC's latest figures are 10yr - 108, 20 yr - 86 and 100yr - 34 times the GHG value of CO2. Shindell et al don't provide 10 year figures but for 20 and 100yr horizons they arrive at figures of 105 and 33 respectively. 

 

Howard quotes the IPCC:

 The IPCC further concludes that at the 10-year timescale, the current global release of methane from all anthropogenic sources exceeds (slightly) all anthropogenic carbon dioxide emissions as agents of global warming; that is, methane emissions are more important (slightly) than carbon dioxide emissions for driving the current rate of global warming. At the 20-year timescale, total global emissions of methane are equivalent to over 80% of global carbon dioxide emissions.

and notes that while long term climate change is driven by CO2 the immediate response is to CH4 and black carbon.

 

He then quotes Shindell's report which was accepted by the UN in 2012:

 unless emissions of methane and black carbon are reduced immediately, the Earth's average surface temperature will warm by 1.5°C by about 2030 and by 2.0°C by 2045 to 2050 whether or not carbon dioxide emissions are reduced.

His fear is that one of the tipping points will be reached within a 20 year time frame making the 100 year responses moot.

 

Seeing the CH4 increases since 2010 and attributing them to recent fracking in the States he believes that we could reach 2C above pre-industrial levels by 2035. My own fear is based on the probability that, particularly in the light of the Ukraine situation, Europe will embrace widespread fracking & they won't be any better at capturing emissions than the US has been.

 

Long Term the problem is certainly CO2. If a tipping point is reached because of CH4 and black carbon the long term doesn't matter.

 

all quotes from from

http://onlinelibrary.wiley.com/enhanced/doi/10.1002/ese3.35#ese335-bib-0034

 

Terry

Link to comment
Share on other sites

I'm just not seeing a big increase in ch4 from Fracking.... It's certainly not showing up in monitoring data. China and Russia just signed a big natural gas agreement, the purpose is to phase out coal. I sure hope this works, it could directly reduce co2 emissions and reduce black carbon emission.

Link to comment
Share on other sites

  • 2 weeks later...
  • 1 month later...

Are there links available to track Gulf of Mexico methane?  I can't tell if changes I have noticed in water vapor behavior in relation to the Gulf of Mexico are from integration of comet dust (ISON & LINEAR) or from possible increased release from underwater that have been theorized to be possible since 2010 and earlier. 

Link to comment
Share on other sites

  • 2 weeks later...

I think most readers on this forum have read the recent reports of large craters being found in Siberia, and the discussion of their origin.  There was a post on the IFLScience website [link] that may be of interest.  Here is an excerpt:

 

An expedition from the Scientific Center of Arctic Studies found methane concentrations of 9.6% at the bottom of the crater – 50,000 times the atmospheric average. The possibility that methane released by melting permafrost produced the crater had been a favored hypothesis from its discovery in mid-July. Nevertheless, plenty of other theories were circulating, and scientists urged caution before leaping to conclusions.

The extraordinary concentration of methane, on the other hand, seems unlikely to be a coincidence, particularly since methane is slightly lighter than air. The 2012 and 2013 summers on the Yamal peninsular, where the crater is, were around 5°C warmer than normal.

Expedition leader Andrei Plekhanov told Nature that the high temperatures probably thawed the permafrost to the point where it collapsed, releasing the trapped methane.

If my math is correct, 9.6% is 96,000 ppm, or 96,000,000 ppb (which is how atmospheric CH4 is usually measured).  Current CH4 readings at Barrow are around 1880 ppb so the crater levels are alarmingly high.  And given that CH4 is lighter than air, those levels aren't the result of CH4 pooling in the deep craters.

 

I think that it would be interesting to monitor the levels on a periodic, say, weekly, basis to learn if the concentration is rising, falling , or stable.

Link to comment
Share on other sites

I think most readers on this forum have read the recent reports of large craters being found in Siberia, and the discussion of their origin.  There was a post on the IFLScience website [link] that may be of interest.  Here is an excerpt:

 

An expedition from the Scientific Center of Arctic Studies found methane concentrations of 9.6% at the bottom of the crater – 50,000 times the atmospheric average. The possibility that methane released by melting permafrost produced the crater had been a favored hypothesis from its discovery in mid-July. Nevertheless, plenty of other theories were circulating, and scientists urged caution before leaping to conclusions.

The extraordinary concentration of methane, on the other hand, seems unlikely to be a coincidence, particularly since methane is slightly lighter than air. The 2012 and 2013 summers on the Yamal peninsular, where the crater is, were around 5°C warmer than normal.

Expedition leader Andrei Plekhanov told Nature that the high temperatures probably thawed the permafrost to the point where it collapsed, releasing the trapped methane.

If my math is correct, 9.6% is 96,000 ppm, or 96,000,000 ppb (which is how atmospheric CH4 is usually measured).  Current CH4 readings at Barrow are around 1880 ppb so the crater levels are alarmingly high.  And given that CH4 is lighter than air, those levels aren't the result of CH4 pooling in the deep craters.

 

I think that it would be interesting to monitor the levels on a periodic, say, weekly, basis to learn if the concentration is rising, falling , or stable.

 

Here's a bit more info and a video.

 

http://www.smh.com.au/environment/climate-change/scientists-may-have-solved-the-giant-siberian-crater-mystery--and-the-news-isnt-good-20140806-100u53.html?utm_source=twitter&utm_medium=social&utm_campaign=nc&eid=socialn%3Atwi-13omn1677-edtrl-other%3Annn-17%2F02%2F2014-edtrs_socialshare-all-nnn-nnn-vars-o%26sa%3DD%26usg%3DALhdy28zsr6qiq

Link to comment
Share on other sites

  • 2 months later...

Not Arctic, but thought I'd share.

http://news.agu.org/press-release/satellite-data-shows-u-s-methane-hot-spot-bigger-than-expected/

SATELLITE DATA SHOWS U.S. METHANE ‘HOT SPOT’ BIGGER THAN EXPECTED

9 October 2014

Joint Release

WASHINGTON, D.C. – One small “hot spot” in the U.S. Southwest is responsible for producing the largest concentration of the greenhouse gas methane seen over the United States – more than triple the standard ground-based estimate — according to a new study of satellite data.

Methane is very efficient at trapping heat in the atmosphere and, like carbon dioxide, it contributes to global warming. The hot spot, near the Four Corners intersection of Arizona, Colorado, New Mexico and Utah, covers only about 6,500 square kilometers (2,500 square miles), or half the size of Connecticut.

This map shows anomalous U.S. methane emissions (that is, how much the emissions are higher or lower than average) for 2003-2009, as measured by SCIAMACHY. Purple and dark blue areas are below average. Pale blue and green areas are close to normal or slightly elevated. Yellows and red indicate higher-than-normal anomalies, with more intense colors showing higher concentrations. The Four Corners area is the only red spot on the map.

satellite-methane-signal-averages.png

This map shows anomalous U.S. methane emissions (or how much the emissions differ from average background concentrations) for 2003 to 2009, as measured by the European Space Agency’s SCIAMACHY instrument. Purple and dark blue areas are below average. Pale blue and green areas are close to normal or slightly elevated. Yellows and red indicate higher-than-normal anomalies, with more intense colors showing higher concentrations. The Four Corners area – the area where Arizona, Colorado, New Mexico and Utah meet — is the only red spot on the map.

Credit:NASA/JPL-Caltech/University of Michigan

In each of the seven years studied from 2003-2009, the area released about 0.59 million metric tons (0.65 million U.S. tons) of methane into the atmosphere. This is almost 3.5 times the estimate for the same area in the European Union’s widely used Emissions Database for Global Atmospheric Research.

In the study published online today in Geophysical Research Letters, a journal of the American Geophysical Union, researchers used observations made by the European Space Agency’s Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instrument. SCIAMACHY measured greenhouse gases from 2002 to 2012. The atmospheric hot spot persisted throughout the study period. A ground station in the Total Carbon Column Observing Network, operated by the Department of Energy’s Los Alamos National Laboratory, provided independent validation of the measurement.

To calculate the emissions rate that would be required to produce the observed concentration of methane in the air, the authors performed high-resolution regional simulations using a chemical transport model, which simulates how weather moves and changes airborne chemical compounds.

Research scientist Christian Frankenberg of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, first noticed the Four Corners signal years ago in SCIAMACHY data.

“We didn’t focus on it because we weren’t sure if it was a true signal or an instrument error,” Frankenberg said.

The study’s lead author, Eric Kort of the University of Michigan, Ann Arbor, noted the study period predates the widespread use of hydraulic fracturing, known as fracking, near the hot spot. This indicates the methane emissions should not be attributed to fracking but instead to leaks in natural gas production and processing equipment in New Mexico’s San Juan Basin, which is the most active coalbed methane production area in the country.

Natural gas is 95-98 percent methane. Methane is colorless and odorless, making leaks hard to detect without scientific instruments.

“The results are indicative that emissions from established fossil fuel harvesting techniques are greater than inventoried,” Kort said. “There’s been so much attention on high-volume hydraulic fracturing, but we need to consider the industry as a whole.”

Coalbed methane is gas that lines pores and cracks within coal. In underground coal mines, it is a deadly hazard that causes fatal explosions almost every year as it seeps out of the rock. After the U.S. energy crisis of the 1970s, techniques were invented to extract the methane from the coal and use it for fuel. By 2012, coalbed methane supplied about 8 percent of all natural gas in the United States.

Frankenberg noted that the study demonstrates the unique role space-based measurements can play in monitoring greenhouse gases.

“Satellite data cannot be as accurate as ground-based estimates, but from space, there are no hiding places,” Frankenberg said.

In March 2014 the Obama Administration announced a strategy to reduce methane emissions under its Climate Action Plan. The strategy includes improving the measurement and monitoring of methane emissions and assessing current methane emissions data.

Link to comment
Share on other sites

  • 4 months later...

and we wonder why cloud tops have been lowering over the years.

 

sky falling yet..?

 

kind of explains why flash floods have been more severe than in the past. 

 

http://www.jpl.nasa.gov/news/news.php?feature=3285
 

 

Scientists at the University of Auckland in New Zealand analyzed the first 10 years of global cloud-top height measurements (from March 2000 to February 2010) from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra spacecraft. The study, published recently in the journal Geophysical Research Letters, revealed an overall trend of decreasing cloud height. Global average cloud height declined by around one percent over the decade, or by around 100 to 130 feet (30 to 40 meters). Most of the reduction was due to fewer clouds occurring at very high altitudes.

Lead researcher Roger Davies said that while the record is too short to be definitive, it provides a hint that something quite important might be going on. Longer-term monitoring will be required to determine the significance of the observation for global temperatures.

 

Link to comment
Share on other sites

  • 2 weeks later...

Here is the CH4 in-situ hourly average data at the Barrow AK observatory.  There does appear to be a plume of CH4 in recent months.

 

 

ccgg.BRW.ch4.4.none.hourly.2006.2015.png

 

Looking at just the 2014 to present data makes it clearer.

 

ccgg.BRW.ch4.4.none.hourly.2014.2015.png

It looks like a series of CH4 events starting last Fall.

Link to comment
Share on other sites

  • 2 months later...

I saw a few minutes of this talk today, casting doubt on large ESAS emissions, in terms of a ship measuring CH4 well offshore in the Laptev Sea. 

 

http://www.esrl.noaa.gov/gmd/annualconference/abs.php?refnum=107-150406-A

 

Shakhova is also quoted in this paper on Carbon-Tracker Methane suggesting no strong trend in the ESAS yet if you read some of the details:

 

http://www.atmos-chem-phys.net/14/8269/2014/acp-14-8269-2014.pdf

Link to comment
Share on other sites

  • 2 weeks later...

An interesting comment at Neven's theorizes that Aug & Sept CH4 levels pack additional punch in the Arctic because the low solar angle forces photons through much more of the GHG polluted atmosphere. 

Terry

It seems that CH4 would be spectrally active more as reradiation in the IR, thus solar radiation (and its angle) wouldn't much of a direct factor? CH4 does absorb some of the shortwave IR radiation coming from the sun though around 3 microns, so here it could have an effect, though I'm unsure which sign it has.

 

On another note, I've seen a skeptical argument that methane has less effect when water vapor is present, since they absorb/emit at some of the same wavelengths. What's the story on that? I suppose that the absorption isn't saturated enough, thus increases in each of these gases remains important.

Link to comment
Share on other sites

  • 4 months later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...