Welcome to DU! The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards. Join the community: Create a free account Support DU (and get rid of ads!): Become a Star Member Latest Breaking News General Discussion The DU Lounge All Forums Issue Forums Culture Forums Alliance Forums Region Forums Support Forums Help & Search

OKIsItJustMe

(19,938 posts)
Tue Apr 18, 2017, 10:56 PM Apr 2017

Banned industrial solvent sheds new light on methane mystery

http://www.bristol.ac.uk/news/2017/april/industrial-solvent-methane.html
[font face=Serif][font size=5]Banned industrial solvent sheds new light on methane mystery[/font]

Press release issued: 17 April 2017

[font size=4]Since 2007, scientists have been searching to find the cause of a sudden and unexpected global rise in atmospheric methane, a potent greenhouse gas, following almost a decade in which concentrations had stayed relatively constant.[/font]

[font size=3]Recent studies have explored a range of possible causes. Suggestions have included a rise in oil and natural gas extraction, increased emissions from tropical wetlands or increases in emissions from growing East Asian economies.

However, a new paper by an international team of scientists in the Proceedings of the National Academy of Sciences (PNAS) investigates an alternative possibility: a rise and fall in the concentration of the substance that destroys methane in the atmosphere, the hydroxyl radical.

Lead author, Dr Matt Rigby from the University of Bristol’s School of Chemistry and Cabot Institute, said: "A change in the hydroxyl radical concentration would be a neat explanation for the changes in methane that we’ve seen.

"It would mean that emissions may not have increased suddenly in 2007, but rather, risen more gradually over the last couple of decades."

…[/font][/font]
https://doi.org/10.1073/pnas.1616426114
3 replies = new reply since forum marked as read
Highlight: NoneDon't highlight anything 5 newestHighlight 5 most recent replies
Banned industrial solvent sheds new light on methane mystery (Original Post) OKIsItJustMe Apr 2017 OP
This message was self-deleted by its author defacto7 Apr 2017 #1
The Bristol Univ. article extensively quotes the authors... kristopher Apr 2017 #2
my apologies defacto7 Apr 2017 #3

Response to OKIsItJustMe (Original post)

kristopher

(29,798 posts)
2. The Bristol Univ. article extensively quotes the authors...
Wed Apr 19, 2017, 08:47 PM
Apr 2017

...and as for the PNAS article not leading to or suggesting a conclusion - Huh?

PNAS Abstract
The growth in global methane (CH4) concentration, which had been ongoing since the industrial revolution, stalled around the year 2000 before resuming globally in 2007. We evaluate the role of the hydroxyl radical (OH), the major CH4 sink, in the recent CH4 growth. We also examine the influence of systematic uncertainties in OH concentrations on CH4 emissions inferred from atmospheric observations. We use observations of 1,1,1-trichloroethane (CH3CCl3), which is lost primarily through reaction with OH, to estimate OH levels as well as CH3CC3 emissions, which have uncertainty that previously limited the accuracy of OH estimates. We find a 64–70% probability that a decline in OH has contributed to the post-2007 methane rise. Our median solution suggests that CH4 emissions increased relatively steadily during the late 1990s and early 2000s, after which growth was more modest. This solution obviates the need for a sudden statistically significant change in total CH4 emissions around the year 2007 to explain the atmospheric observations and can explain some of the decline in the atmospheric 13CH4/12CH4 ratio and the recent growth in C2H6. Our approach indicates that significant OH-related uncertainties in the CH4 budget remain, and we find that it is not possible to implicate, with a high degree of confidence, rapid global CH4 emissions changes as the primary driver of recent trends when our inferred OH trends and these uncertainties are considered.


defacto7

(13,485 posts)
3. my apologies
Wed Apr 19, 2017, 11:50 PM
Apr 2017

I wasn't thinking straight last evening. I shouldn't reply to posts when, how should I put it... when my head's off line.

Latest Discussions»Issue Forums»Environment & Energy»Banned industrial solvent...