Methane

Methane (CH₄) absorbs much more energy per unit weight of gas than CO₂. But since methane on average disappears from the atmosphere over a 10-year period, it is difficult to compare the effect of methane against CO₂ directly. Over a 100-year period, methane will have a potential for global warming (global warming potential - GWP) which is 28-36 times larger than CO₂ [L30]. For a shorter period, the GWP for CH₄ will be higher, since CO₂ will continue to absorb energy long after the shorter period is over.

Fortunately, methane emissions are significantly lower than CO₂ emissions, which is reflected in the measurements of methane concentration in the atmosphere [L31]:

According to this figure, the average methane concentration in 2019 was about 1860 ppb (= 1.86 ppm). The CO₂ concentration was by comparison about 408 ppm.

Latest update: 2021-07-13