Anthropogenic sources of methane include leaks during fossil fuel mining, rice agriculture, raising livestock (cattle and sheep), and municipal landfills. Methanogens thrive in the oxygen-free (anaerobic) environment of landfills, releasing the gas in significant quantities. The gas is purposefully ignited to prevent explosion or captured for its commercial value as a fuel.
Livestock such as sheep, goats, camel, cattle, and buffalo currently account for 15 percent of the annual anthropogenic methane emissions
So from that I would guess at deforestation as that releases CO2 not methane but yeah. I go the info of google. Hope this helps :)