Like carbon dioxide, methane is one of the most important greenhouse gases. After a period of stagnation around 2000, atmospheric methane concentrations started to rise again in 2007. So far, the causes have been unknown. According to the recent study of climate scientists at least 40 percent of this increase result from the growing production of oil and natural gas in the northern hemisphere.
from Geochemistry News -- ScienceDaily http://ift.tt/1WpeftJ