[aslkahuna]

In terms of its ability to absorb IR Methane is very much more effective than CO2. A flammable mix of Methane in the atmosphere would contain far more Methane than the amount in parts per billion needed to equal the IR absorbing ability of the current amount of 388 parts per million of CO2. Currently, the majority of Methane is sequestered in Permafrost layers and in Methane Hydrate deposits in the Oceans the release of large quantites of either would result in Methane levels certainly capable of equalling or exceeding the effects of CO2 without ever reaching a point where it would be a flammable mix. It's the Permafrost Methane that is most worrisome to some as it melts with the increase in temperatures in the high latitudes which is expected to be greater than in the lower latitudes. BTW Methane already exists as a trace GHG in our atmosphere and it hasn't caught fire yet. Incidentally, lightning occurs in the Jovian and Saturnian atmsophere all of the time with far greater energy and temperature and there are large quantities of Methane in both atmospheres and they haven't caught fire yet. Because of the high temperature of a lightning discharge it's more likely to result in disassociation, ionization and formation of a plasma rather than a fire involving atmospheric gases.

Steve