Methane in atmosphere 4680tons

Loss by chemical reaction520 TONS/YR -57 per mil 0.8

Natural wetlands tons/yr

W-65 per mil1.0

Biomass burning tons/yrB-20 per mil1.0

Fossil fuelassociated emissionstons/yrF -40 per mill0

Below is a picture showing the amount of methane in the atmosphere (3500 Tg = 3500 tons) and the major processes adding methane to and removing methane from the atmosphere. Units are all in metric tons (or 106 grams) and metric tons/year of methane

W+B+F = 520W*(-65) +B(-20) + F*(-40) = 520*(-57)W*1.0 + B(1.0) +F*0 = 520*0.8

https://webfiles.uci.edu/setrumbo/public/IMPRS/fossil%20fuels.xls?uniq=-1o7yls

Southern hemisphere Northern hemisphere

V = volume of air in hemispehre (assume equal in N, S)Xn, Xs = mixing ratio of CO2 in N, S (assume 315 in 1958)Rate of exchange between hemispheres is V/1yrFor F, B see spreadsheet

VXn

F fossil fuel)

B/2 B/2S S

VXs

VdXs (t)/dt =VXn(t-1)/1yr +B/2 – SVdsXn (t)/dt = VXs(t-1)/1yr +B/2 –S +FS+S =(1- 0.57)F = 0.43 FVdXn/dt + VdXs/dt = 0.57F

https://webfiles.uci.edu/setrumbo/public/IMPRS

Moles air in atmosphere =2V = [1.78 x 10^20] Moles CO2 in air in 1950 = 315 x 10^-6 * 1.78 x 10^20 moles