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Originally Posted by REASON
5. Methane is a much stronger greenhouse gas than CO2. Should we be concerned about increasing global warming if Methane fuel were to become widely used?
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Quote:
Originally Posted by modest
Good question! I'll look into it.
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Quote:
Originally Posted by Boerseun
The fear of methane as a greenhouse gas is a bit overstated, I reckon.
Methane can't exist in an oxygen-rich atmosphere for very long - oxygen just kills it, man.
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After looking this up, I quickly came to the same conclusion as Boerseun. Methane is a powerful greenhouse gas, but has a short
atmospheric life of only approximately 12 years. Any given methane molecule that is released into the atmosphere will last about 12 years before decomposing into water and carbon dioxide:
A useful way of expressing the effect of a greenhouse gas is by calculating the
Global Warming Potential. This was the agreed upon standard at Kyoto. The result of the calculation shows how harmful something is as a greenhouse gas compared to carbon dioxide over a period of time. Methane is:
Meaning that spilling an equal amount of methane as carbon dioxide is sixty two times worse over 20 years, 23 times worse over 100 years, and 7 times worse over 500 years.
Compared to some CFCs and HFCs which remain at hundreds or thousands of times worse than
over hundreds of years, methane is not too awfully environmentally destructive.
I would, however, like to note again that burning methane or natural gas produces carbon dioxide no different than petrol. There are environmental advantages to using natural gas vehicles such as far less carbon monoxide and particulate pollution. But, natural gas has a carbon footprint like any fossil fuel. NGV's are therefore neither a completely clean nor completely green substitute.
As it relates to this thread on the other hand - natural gas vehicles cost a third less “at the pump”. That would be nice.
