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Author Topic: Trends in atmospheric CH4  (Read 12366 times)

Shared Humanity

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Re: Trends in atmospheric CH4
« Reply #50 on: February 09, 2020, 07:37:43 PM »
I second Oren with the thanks. Tracking these atmospheric levels of greenhouse gases is the single best way to measure the adequacy of our efforts to avoid catastrophic warming. You are doing this site a service by providing these updates which serve as a context for discussions on many threads on this site. The numbers are not good but necessary.

Stephan

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Re: Trends in atmospheric CH4
« Reply #51 on: February 09, 2020, 09:00:58 PM »
Thank you SH.
I try to be as early and as reliable (concerning the time I find to do the posting and to compare the actual data with older ones and compute slopes) as possible. Just a number (x,yyy.z ppb) is in my opinion not enough to feed a discussion.
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dnem

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Re: Trends in atmospheric CH4
« Reply #52 on: February 19, 2020, 09:54:31 PM »
https://www.nature.com/articles/s41586-020-1991-8

Preindustrial 14CH4 indicates greater anthropogenic fossil CH4 emissions

Abstract
Atmospheric methane (CH4) is a potent greenhouse gas, and its mole fraction has more than doubled since the preindustrial era1. Fossil fuel extraction and use are among the largest anthropogenic sources of CH4 emissions, but the precise magnitude of these contributions is a subject of debate2,3. Carbon-14 in CH4 (14CH4) can be used to distinguish between fossil (14C-free) CH4 emissions and contemporaneous biogenic sources; however, poorly constrained direct 14CH4 emissions from nuclear reactors have complicated this approach since the middle of the 20th century4,5. Moreover, the partitioning of total fossil CH4 emissions (presently 172 to 195 teragrams CH4 per year)2,3 between anthropogenic and natural geological sources (such as seeps and mud volcanoes) is under debate; emission inventories suggest that the latter account for about 40 to 60 teragrams CH4 per year6,7. Geological emissions were less than 15.4 teragrams CH4 per year at the end of the Pleistocene, about 11,600 years ago8, but that period is an imperfect analogue for present-day emissions owing to the large terrestrial ice sheet cover, lower sea level and extensive permafrost. Here we use preindustrial-era ice core 14CH4 measurements to show that natural geological CH4 emissions to the atmosphere were about 1.6 teragrams CH4 per year, with a maximum of 5.4 teragrams CH4 per year (95 per cent confidence limit)—an order of magnitude lower than the currently used estimates. This result indicates that anthropogenic fossil CH4 emissions are underestimated by about 38 to 58 teragrams CH4 per year, or about 25 to 40 per cent of recent estimates. Our record highlights the human impact on the atmosphere and climate, provides a firm target for inventories of the global CH4 budget, and will help to inform strategies for targeted emission reductions9,10.


Stephan

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Re: Trends in atmospheric CH4
« Reply #53 on: March 06, 2020, 08:41:18 PM »
Finally, also CH4 received an update by NOAA:

November 2019:     1877.0 ppb
November 2018:     1866.2 ppb
Last updated: March 05, 2020

This converts into CO2 eq: 57.3 / 19.1 ppm (20 y / 100 y)

The annual increase of 10.8 ppb is at the very upper end of what has been observed in the last years. You have to go back to 2015/16 to find comparable rates.

I set an index of 100 to Jan 2000. November 2019 has a relative value of 105.7.
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Stephan

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Re: Trends in atmospheric CH4
« Reply #54 on: April 06, 2020, 09:00:30 PM »
Finally, also CH4 received an update by NOAA:

December 2019:     1874.7 ppb
December 2018:     1866.0 ppb
Last updated: April 05, 2020

The 2019 average is thus 1866.9 ppb, 9.5 ppb above the 2018 average.

This converts into CO2 eq: 57.3 / 19.1 ppm (20 y / 100 y)

The annual increase of 8.7 ppb is in the upper half of what has been observed in the last years, but much lower than in July-November 2019 (see posts above in this thread).

I set an index of 100 to Jan 2000. December 2019 has a relative value of 105.6.
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Stephan

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Re: Trends in atmospheric CH4
« Reply #55 on: May 05, 2020, 10:26:28 PM »
It is the fifth of the new month and so the average values of the "NOAA gases" are available.
Here is the value of CH4:

January 2020:     1873.5 ppb
January 2019:     1865.0 ppb
Last updated: May 05, 2020

This converts into CO2 eq: 57.2 / 19.1 ppm (20 y / 100 y)

The annual increase of 8.5 ppb is in the upper half of what has been observed in the last years, but much lower than in July-November 2019 (see posts above in this thread).

I set an index of 100 to Jan 2000. January 2020 has a relative value of 105.5.
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Stephan

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Re: Trends in atmospheric CH4
« Reply #56 on: June 05, 2020, 09:25:14 PM »
It is the fifth of the new month. Therefore the monthly averages of the "NOAA gases" are available. Here is the value of CH4:

February 2020:     1873.7 ppb
February 2019:     1864.9 ppb
Last updated: June 05, 2020

This is an annual increase of 8.8 ppb. This increase is still in the upper half of what has been observed in the last years.

I set an index = 100 for the 1980 average [1601.2 ppb]. February 2020 is at 117.0 compared to that index.
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Stephan

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Re: Trends in atmospheric CH4
« Reply #57 on: July 06, 2020, 09:13:58 PM »
It is the fifth of the new month. Therefore the monthly averages of the "NOAA gases" are available. Here is the value of CH4:

March 2020:     1876.4 ppb
March 2019:     1866.3 ppb
Last updated: July 05, 2020

This is an annual increase of 10.1 ppb. This increase is in the upper half of what has been observed in the last years.

I set an index = 100 for the 1980 average [1601.2 ppb]. March 2020 is at 117.2 compared to that index.
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Stephan

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Re: Trends in atmospheric CH4
« Reply #58 on: August 06, 2020, 07:36:11 PM »
It is the fifth of the new month. Therefore the monthly averages of the "NOAA gases" are available. Here is the value of CH4:

April 2020:     1876.3 ppb
April 2019:     1865.3 ppb
Last updated: August 05, 2020

This is an annual increase of 11.0 ppb. This increase is in the upper half of what has been observed in the last years.

I set an index = 100 for the 1980 average [1601.2 ppb]. April 2020 is at 117.2 compared to that index.

Attached the development since 1980. A much more complicated pattern than the CO2, N2O or SF6 graphs.
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Stephan

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Re: Trends in atmospheric CH4
« Reply #59 on: September 10, 2020, 08:32:31 PM »
Here is the latest monthly average of Mauna Loa CH4 concntration:

May 2020:     1874.7 ppb
May 2019:     1861.9 ppb
Last updated: September 05, 2020

This is an annual increase of 12.8 ppb. This is the highest annual increase since March 2015!

I set an index = 100 for the 1980 average [1601.2 ppb]. May 2020 is at 117.1 compared to that index.

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Stephan

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Re: Trends in atmospheric CH4
« Reply #60 on: October 06, 2020, 08:35:52 PM »
Here is the latest monthly average of Mauna Loa CH4 concentration:

June 2020:     1872.2 ppb
June 2019:     1858.8 ppb
Last updated: October 05, 2020

This is an annual increase of 13.4 ppb. This is the highest annual increase since February 2015!

I set an index = 100 for the 1980 average [1601.2 ppb]. June 2020 is at 116.9 compared to that index.
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Stephan

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Re: Trends in atmospheric CH4
« Reply #61 on: November 06, 2020, 07:09:21 PM »
Here is the latest monthly average of Mauna Loa CH4 concentration:

July 2020:     1872.0 ppb
July 2019:     1858.4 ppb
Last updated: November 05, 2020

This is an annual increase of 13.6 ppb. This is the highest annual increase since February 2015!

I set an index = 100 for the 1980 average [1601.2 ppb]. July 2020 is at 116.9 compared to that index.

See attached graph. Click for a better visibility
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oren

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Re: Trends in atmospheric CH4
« Reply #62 on: November 06, 2020, 10:48:29 PM »
Thanks for the charts Stephan, a welcome addition, showing well the worrying trends.

Stephan

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Re: Trends in atmospheric CH4
« Reply #63 on: November 06, 2020, 10:53:14 PM »
...you're welcome, oren.
I will add the charts from time to time. Just yesterday I thought it would be time for another set of actualized "NOAA gases" chart, and so I included them in my posting.
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grixm

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Re: Trends in atmospheric CH4
« Reply #64 on: November 25, 2020, 09:34:38 AM »
A bit of a different perspective. In June/July, the methane concentration usually dips below the value from the preceding winter. However, this year, this effect was very limited. The value is barely below the last local minimum from February. The last time something similar happened was in 2014, and back then what happened next was the biggest autumn jump we've seen since the 20th century, with the winter of 2015 being around 15-16 ppm higher than the winter of 2014. Will this happen this year too?

GoSouthYoungins

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Re: Trends in atmospheric CH4
« Reply #65 on: November 29, 2020, 09:16:39 PM »
I made an little image showing the lack of decrease this year.

big time oops

FishOutofWater

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Re: Trends in atmospheric CH4
« Reply #66 on: November 30, 2020, 02:17:49 AM »
Methane releases from well development of newly fracked wells should be down this spring and summer because of low demand for oil and gas during the pandemic. The large increase this year is concerning because it should not have happened. It will be interesting to see if there's an isotopic shift in any of the measurements. Increases in tropical agriculture have been blamed for much of the rising methane over the past decade, but there is no unique solution to the available isotopic data. Isotopic changes in response to the pandemic could help single out the individual contributions, especially the impacts of fracking on methane levels.

Ken Feldman

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Re: Trends in atmospheric CH4
« Reply #67 on: November 30, 2020, 07:16:44 PM »
Wildfires also release a lot of methane.

The year started with record wildfires in Australia and continued with record wildfires in North America.

And even though active wells were down, abandoned wells were up.  Unfortunately, there aren't enough resources collected from the oil industry to have them plug leaking abandoned wells quickly.

Stephan

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Re: Trends in atmospheric CH4
« Reply #68 on: December 08, 2020, 09:45:19 PM »
Here is the latest monthly average of Mauna Loa CH4 concentration:

August 2020:     1876.9 ppb
August 2019:     1863.0 ppb
Last updated: December 05, 2020

This is an annual increase of 13.9 ppb. This is the highest annual increase since February 2015!

I set an index = 100 for the 1980 average [1601.2 ppb]. August 2020 is at 117.2 compared to that index.
« Last Edit: December 08, 2020, 10:06:09 PM by Stephan »
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grixm

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Re: Trends in atmospheric CH4
« Reply #69 on: December 17, 2020, 11:40:05 PM »
I noticed that this August had a higher CH4 concentration than any other month in the year before it. Closest was April at 0.4 ppb less. In other words it's the all-time high.

That has never happened for any other August since records began.

Tom_Mazanec

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Re: Trends in atmospheric CH4
« Reply #70 on: December 17, 2020, 11:43:41 PM »
Does methane have any seasonal patterns?
SHARKS (CROSSED OUT) MONGEESE (SIC) WITH FRICKIN LASER BEAMS ATTACHED TO THEIR HEADS

kassy

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Re: Trends in atmospheric CH4
« Reply #71 on: December 18, 2020, 02:12:14 PM »
Check the graphic in #65.
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

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Re: Trends in atmospheric CH4
« Reply #72 on: December 18, 2020, 02:47:05 PM »
So if I read that graphic right, it used to have a seasonal pattern but it is now rising so fast that the secular increase is swamping the annual ups and downs?
SHARKS (CROSSED OUT) MONGEESE (SIC) WITH FRICKIN LASER BEAMS ATTACHED TO THEIR HEADS

kassy

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Re: Trends in atmospheric CH4
« Reply #73 on: December 18, 2020, 03:21:12 PM »
No it still has a seasonal peak late in the year (and notice the scale).
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

Stephan

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Re: Trends in atmospheric CH4
« Reply #74 on: December 18, 2020, 09:33:24 PM »
Just for clarification. There is a typical seasonal pattern in CH4 concentration. After the seasonal minimum in July the values rise fast to the November (sometimes December) maximum. After that there is a slow decrease into a "semi" minimum in January or February. After that a small increase into the March "semi" maximum which then rapidly falls into the next July minimum.
Usually the March "semi" maximum is smaller than the preceding November maximum, but this is not always the case (e.g. 2007, 2010, 2019). As for all natural phenomena there is a certain variability concerning the detailed pattern and values. So each year looks different. What surprised me is the relatively small minimum in July 2020.
I pointed out the relevant features in the attached graph (2016 - 2020). The heights of the lines roughly indicate the differences between maxima and minima.
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kassy

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Re: Trends in atmospheric CH4
« Reply #75 on: December 18, 2020, 10:22:36 PM »
Thanks for that. Is there an easy way to show earlier years? Mainly curious about the pattern between the peaks,
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

grixm

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Re: Trends in atmospheric CH4
« Reply #76 on: December 18, 2020, 11:40:06 PM »
Thanks for that. Is there an easy way to show earlier years? Mainly curious about the pattern between the peaks,

https://www.methanelevels.org/

kassy

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Re: Trends in atmospheric CH4
« Reply #77 on: December 19, 2020, 01:54:05 AM »
That does not show them it is just the general trend.
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

grixm

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Re: Trends in atmospheric CH4
« Reply #78 on: December 19, 2020, 08:27:55 AM »
That does not show them it is just the general trend.

Zoom in. That chart has every data point there is.

kassy

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Re: Trends in atmospheric CH4
« Reply #79 on: December 19, 2020, 11:33:20 AM »
Ah right i only saw all the pre 1980ies yearly data which ofc does not help, thx!
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

Stephan

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Re: Trends in atmospheric CH4
« Reply #80 on: December 19, 2020, 08:53:02 PM »
Thanks for that. Is there an easy way to show earlier years? Mainly curious about the pattern between the peaks,

Here you go, kassy:

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Re: Trends in atmospheric CH4
« Reply #81 on: December 19, 2020, 09:54:40 PM »
See the pause from 2003 to 2011
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Stephan

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Re: Trends in atmospheric CH4
« Reply #82 on: January 12, 2021, 10:24:24 PM »
Almost a week later than usual an update of global CH4 is available from NOAA:

September 2020:     1884.0 ppb
September 2019:     1870.7 ppb
Last updated: January 05, 2021

This is an annual increase of 13.3 ppb. This is the third highest annual increase since February 2015 and way above the 10 y average increase of 7.78 ppb/a.

I set an index = 100 for the 1980 average [1601.2 ppb]. September 2020 is at 117.7 compared to that index.
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