Thread by @ncdave4life

@Mark_A_Lunn @ammocrypta @flyonthewall182 @1tsakeeper @BrknMan @TWTThisIsNow @glinch72 @Willard1951 @KCTaz @Climatehope2 @AristotleMrs @JohnDublin10 @FChecker76 @geoguy_usa104 @Stephen90045069 @NonlinearDarren @GregTruman4 @Jaisans @GregCoo85844909 @25_cycle @don85375 @ZSRenn @LizHersch1 @JustThi30117912 @gregchoat @Anvndarnamn5 @B_Bolshevik100 @NickMcGinley1 @RobMeekel @cieloyla @EthonRaptor @BradPKeyes @JSegor @BridgetHolmstro @jwickers @0Sundance @PeterMayfitz @omahas @TonyBoloni8 @TheDisproof @DanCady @dan613 @Keeper_86 @Jamz129 @CallMeBlaise1 @ostinado @IngersolRobert @CarrudoDon @DK25769559 1/8. Even if you don't burn it, methane (CH4) oxidizes into harmless CO2 and water vapor:
sealevel.info/methane.html

This is very simplified:
CH4 + 2⋅O2 → CO2 + 2⋅H2O
Here are details:
acmg.seas.harvard.edu/people/faculty…

Current average CH4 level is ≈1.88 ppmv
sealevel.info/ch4.html

@Mark_A_Lunn @ammocrypta @flyonthewall182 @1tsakeeper @BrknMan @TWTThisIsNow @glinch72 @Willard1951 @KCTaz @Climatehope2 @AristotleMrs @JohnDublin10 @FChecker76 @geoguy_usa104 @Stephen90045069 @NonlinearDarren @GregTruman4 @Jaisans @GregCoo85844909 @25_cycle @don85375 @ZSRenn @LizHersch1 @JustThi30117912 @gregchoat @Anvndarnamn5 @B_Bolshevik100 @NickMcGinley1 @RobMeekel @cieloyla @EthonRaptor @BradPKeyes @JSegor @BridgetHolmstro @jwickers @0Sundance @PeterMayfitz @omahas @TonyBoloni8 @TheDisproof @DanCady @dan613 @Keeper_86 @Jamz129 @CallMeBlaise1 @ostinado @IngersolRobert @CarrudoDon @DK25769559 2/8. Various sources give the half-life of CH4 in the atmosphere as 6 - 8 years, making the average lifetime 1.4427 times that (because oxidation is an exponential process, rather than linear), yielding average lifetime for a molecule of CH4 in the atmosphere of 8.7 - 11.5 years.

@Mark_A_Lunn @ammocrypta @flyonthewall182 @1tsakeeper @BrknMan @TWTThisIsNow @glinch72 @Willard1951 @KCTaz @Climatehope2 @AristotleMrs @JohnDublin10 @FChecker76 @geoguy_usa104 @Stephen90045069 @NonlinearDarren @GregTruman4 @Jaisans @GregCoo85844909 @25_cycle @don85375 @ZSRenn @LizHersch1 @JustThi30117912 @gregchoat @Anvndarnamn5 @B_Bolshevik100 @NickMcGinley1 @RobMeekel @cieloyla @EthonRaptor @BradPKeyes @JSegor @BridgetHolmstro @jwickers @0Sundance @PeterMayfitz @omahas @TonyBoloni8 @TheDisproof @DanCady @dan613 @Keeper_86 @Jamz129 @CallMeBlaise1 @ostinado @IngersolRobert @CarrudoDon @DK25769559 3/8. Page 11 of this source gives the directly-calculated atmospheric lifetime of CH4 as ~8 years, but identifies a feedback mechanism that (they say) effectively increases the atmospheric lifetime of additional CH4 to ~12 years.

faculty.washington.edu/jaegle/558/ox_…

@Mark_A_Lunn @ammocrypta @flyonthewall182 @1tsakeeper @BrknMan @TWTThisIsNow @glinch72 @Willard1951 @KCTaz @Climatehope2 @AristotleMrs @JohnDublin10 @FChecker76 @geoguy_usa104 @Stephen90045069 @NonlinearDarren @GregTruman4 @Jaisans @GregCoo85844909 @25_cycle @don85375 @ZSRenn @LizHersch1 @JustThi30117912 @gregchoat @Anvndarnamn5 @B_Bolshevik100 @NickMcGinley1 @RobMeekel @cieloyla @EthonRaptor @BradPKeyes @JSegor @BridgetHolmstro @jwickers @0Sundance @PeterMayfitz @omahas @TonyBoloni8 @TheDisproof @DanCady @dan613 @Keeper_86 @Jamz129 @CallMeBlaise1 @ostinado @IngersolRobert @CarrudoDon @DK25769559 4/8. Call it 8-12 yrs. That's short. It means the only reason CH4 levels are high (≈1.88 ppmv) is CH4 emissions (natural + anthropogenic) are already high. There'd have to be a very large, sustained increase in CH4 emissions to cause much increase in long-term average CH4 level.

@Mark_A_Lunn @ammocrypta @flyonthewall182 @1tsakeeper @BrknMan @TWTThisIsNow @glinch72 @Willard1951 @KCTaz @Climatehope2 @AristotleMrs @JohnDublin10 @FChecker76 @geoguy_usa104 @Stephen90045069 @NonlinearDarren @GregTruman4 @Jaisans @GregCoo85844909 @25_cycle @don85375 @ZSRenn @LizHersch1 @JustThi30117912 @gregchoat @Anvndarnamn5 @B_Bolshevik100 @NickMcGinley1 @RobMeekel @cieloyla @EthonRaptor @BradPKeyes @JSegor @BridgetHolmstro @jwickers @0Sundance @PeterMayfitz @omahas @TonyBoloni8 @TheDisproof @DanCady @dan613 @Keeper_86 @Jamz129 @CallMeBlaise1 @ostinado @IngersolRobert @CarrudoDon @DK25769559 5/8. With CH4 & CH2 at current levels, it's calculated by both MODTRAN Tropical Atmosphere and the NCAR Radiation Code that a 0.1 ppmv increase in atmospheric methane level has about the same warming effect as a 4.5 ppmv increase in CO2 level.

@Mark_A_Lunn @ammocrypta @flyonthewall182 @1tsakeeper @BrknMan @TWTThisIsNow @glinch72 @Willard1951 @KCTaz @Climatehope2 @AristotleMrs @JohnDublin10 @FChecker76 @geoguy_usa104 @Stephen90045069 @NonlinearDarren @GregTruman4 @Jaisans @GregCoo85844909 @25_cycle @don85375 @ZSRenn @LizHersch1 @JustThi30117912 @gregchoat @Anvndarnamn5 @B_Bolshevik100 @NickMcGinley1 @RobMeekel @cieloyla @EthonRaptor @BradPKeyes @JSegor @BridgetHolmstro @jwickers @0Sundance @PeterMayfitz @omahas @TonyBoloni8 @TheDisproof @DanCady @dan613 @Keeper_86 @Jamz129 @CallMeBlaise1 @ostinado @IngersolRobert @CarrudoDon @DK25769559 6/8. Some other authorities estimate more or less than that 45:1 ratio, e.g., the IPCC's AR5 Table 8.A.1 estimates 26.5:1.
fluorocarbons.org/wp-content/upl…
sealevel.info/AR5_Table_8.A.…

@Mark_A_Lunn @ammocrypta @flyonthewall182 @1tsakeeper @BrknMan @TWTThisIsNow @glinch72 @Willard1951 @KCTaz @Climatehope2 @AristotleMrs @JohnDublin10 @FChecker76 @geoguy_usa104 @Stephen90045069 @NonlinearDarren @GregTruman4 @Jaisans @GregCoo85844909 @25_cycle @don85375 @ZSRenn @LizHersch1 @JustThi30117912 @gregchoat @Anvndarnamn5 @B_Bolshevik100 @NickMcGinley1 @RobMeekel @cieloyla @EthonRaptor @BradPKeyes @JSegor @BridgetHolmstro @jwickers @0Sundance @PeterMayfitz @omahas @TonyBoloni8 @TheDisproof @DanCady @dan613 @Keeper_86 @Jamz129 @CallMeBlaise1 @ostinado @IngersolRobert @CarrudoDon @DK25769559 7/8. But here's the thing: while CO2 levels are rising ≈2.5 ppmv per year, CH4 levels are rising at less than 0.01 ppmv per year. That means the rise in CH4 level causes only about 1/10 the forcing of the rise in CO2 level (using AR5 numbers) or 1/6 (using MODTRAN/NCAR numbers).