Methane is twenty times more damaging to the environment than carbon dioxide, but is not being tracked as closely. Within the last hundred years, methane emissions have risen about twenty-fold from 0.5 parts per billion to 10.0 parts per billion. Because methane isn’t tracked as closely, we also don’t know the sources of the emissions. One worrisome possibility is that the methane is being produced due to agriculture, which necessarily rises with population; and also naturally as rising temperatures encourage bacterial growth and also release stored methane in sea water. As a result, even if we manage to contain CO2 emissions, the planet may warm past the critical 2C threshold due to methane. Without understanding the methane sources soon, we may not be able to control them sufficiently.
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