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Author Topic: "Methane leaks could negate climate benefits of US natural gas boom" The Gaurdia  (Read 2390 times)


shmengie

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This paper explains well, what had already come to believe is a looming problem with "human" / fossil fuel fracking.

http://www.eeb.cornell.edu/howarth/publications/f_EECT-61539-perspectives-on-air-emissions-of-methane-and-climatic-warmin_100815_27470.pdf

Can't help believing a significant portion sudden polar ice vanishing act is related to methane leaked from Aliso Canyon, California.

Not a definitive direct link...  El Nino, excessive persistent fracking, warmer oceans and unrelenting CO₂ play a role as well, I'm sure...  The timing seems chronologically significant, IMO.
Professor Trump, who'd thought it was that complicated?

AbruptSLR

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The following linked reference on GTP and GWP for short-term forcers, indicates a GWP100 for methane of 35:

W. J. Collins, M. M. Fry, H. Yu, J. S. Fuglestvedt, D. T. Shindell, and J. J. West (2013), "Global and regional temperature-change potentials for near-term climate forcers", Atmos. Chem. Phys., 13, 2471–2485, doi:10.5194/acp-13-2471-2013


http://www.atmos-chem-phys.net/13/2471/2013/acp-13-2471-2013.pdf

Therefore,following NOAA's 2015 data the value of CO2-e of 485ppm for 2015 was calculated using GWP100 of 25; so when I use a GWP100 of 35, I get a CO2-e of 518ppm:


http://esrl.noaa.gov/gmd/aggi/aggi.html


         Global Radiative Forcing, CO2-equivalent mixing ratio, and the AGGI 1979-2013
                         Global Radiative Forcing (W m-2)           CO2-eq
                                                                                     (ppm)        AGGI
Year     CO2     CH4    N2O   CFC12 CFC11 15-minor  Total Total   1990 = 1   %change

2013   1.882  0.496   0.184   0.167   0.059   0.114  2.901   478      1.340        2.0
2014   1.908  0.499   0.187   0.166   0.058   0.116  2.935   481      1.356        1.6
2015   1.939  0.504   0.190   0.165   0.058   0.118  2.974   485      1.374        1.8

CH4   ΔF = β(M½ - Mo½) - [f(M,No) - f(Mo,No)]   β = 0.036

This gives a better idea of how much policy maker's are underestimating the current contributions of methane to global warming.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

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My last post used a GWP100 for methane of 35; however, estimates of combined natural and anthropogenic methane emission rates through 2100 justify the use of the findings from Isaksen et al's 7 x CH4 case for calculating a revised GWP for methane, as follows:
 
As the radiative forcing in a 50-year time horizon for 4 x CH4 additional emission of 0.80 GtCH4/yr is 2.2 Wm-2, and as the radiative forcing for the current methane emissions is 0.48 Wm-2, thus an updated GWP for methane, assuming the occurrence of Isaksen et al's 4 x CH4 case in 2040, would be: 33 (per Shindell et al 2009) times (2.2/[0.8 + 0.48]) divided by (0.54/0.48) = 50 by 2100.
 
If the GWP of methane increases to 50 by 2100 then the RCP 8.5 scenario will significantly under-estimate global warming by the end of this century.

Isaksen, I. S. A., Gauss M., Myhre, G., Walter Anthony, K. M.  and Ruppel, C.,  (2011), "Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions", Global Biogeochem. Cycles, 25, GB2002, doi:10.1029/2010GB003845
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson