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Large potential future methane emissions from Arctic permafrost Ivar S.A. Isaksen CICERO

Large potential future methane emissions from Arctic permafrost Ivar S.A. Isaksen CICERO. CH 4 +OH → CH 3 + H 2 O. Global increase in NOx, CO and methane tend to increase tropospheric ozone Increases in tropospheric ozone will increase OH through the reaction :

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Large potential future methane emissions from Arctic permafrost Ivar S.A. Isaksen CICERO

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  1. Large potentialfuturemethaneemissions from Arctic permafrostIvar S.A. IsaksenCICERO

  2. CH4+OH → CH3+ H2 O Global increase in NOx, CO and methanetend to increasetroposphericozone Increases in troposphericozonewillincrease OH throughthereaction: HO2+O3→ OH + 2O2

  3. Methaneemission Indirecteffect: • Increasesitsownlifetimethroughthereactionwiththehydroxylradical (OH) • Current feedback factor: Approx. 0.4 Importantchemicalreactions: • Producesozone in the UTLS region • Produces water vapour in thestratosphere • Produces CO2 in theatmosphere Global methaneemission: • Total current GWP due to methanerelease: Approx. 25 • Increaseswithlargemethaneemissionincreases in the Arctic

  4. Oslo CTM3 – testing large CH4 emissions • Hydrate emissions from Siberian shelf 1000Tg(CH4)/year • Emitted during Jun-Nov • Emission period: 10 years • Simulating additional 15 years of normal emissions

  5. Changes in atmosphericmethaneburden for 10 yearsof 1000 Tg/yearemission in 10 years The burdenincreases from 4800 Tg to 12.0 Tg It is reduced to 7.2 Tg after 15 yearsofnoextraemission

  6. Change in averageatmosphericmethanelifetime for a 1000 Tg /year methaneemission from the Arctic over 100 years Averagebackgroundatmosphericmethanelifetime: 8.6 years After 10 yearsof 1000 Tg/yearemission from the Arctic: 11.6 years

  7. Predictedlargeozone and methaneenhancement from methaneemissions

  8. Changes in methane and ozone 15 years after the emission period Methane and ozonerecovery is fast, takesonly a fewdecades

  9. Factsyouneed to knowaboutthe Arctic methanetimebomb Dismissalsofcatastrophicmethanedangerignore robust science in favourofoutdatedmythologyofclimatesafety Whythejury's still outonthe risk of Arctic methanecatastrophe. Can scientists overcome huge uncertainties to pin downhowclose, or far, wemight be to a tipping point? One sourceoftheseemissions "may be highlypotential and extremely mobile shallowmethanehydrates, whosestabilityzone is seabed permafrost-related and could be disturbedupon permafrost development, degradation, and thawing.” From SkepticalScience: "There is noevidencethatmethanewill run outofcontrol and initiateanysudden, catastrophiceffects."

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