20th October, 2009 - Posted by admin - Comments Off
Here is a reference, which explains the reason methane should be taken more seriously than its “25 times CO2″ label:
Because methane’s impact is relatively short-term (10 years or so) it’s 10, 20 or 50 year Global Warming Potentials are much higher than the conventional 100 year measure. Using a different measure than GWP, the paper compares the effect of permanently preventing 1kg of methane a year reaching the atmosphere compared with CO2. The figures they give are:
- 81 times CO2 (measured over 20 years),
- 57 times CO2 (measured over 50 years)
- 39 times CO2 (measured over 100 years).
We have only 10 or 20 years to get to grips with climate change. On this time scale even the Wikipedia entry on the GWP of methane gives much higher figures than the conventional 25 times CO2.
This analysis does not consider the possibilities of tipping points. We know that certain really scary tipping points are possible but don’t know when they might happen. This makes short-term impacts even more important – the climate may have tipped before we realise it.
We should not underestimate methane.