The authors note that the release of methane increases with increasing temperature. (realclimate.org)
An increase in agriculture, including rice and livestock, may be helping to drive methane increases since 2006. (sciencemag.org)
Dlugokencky, E.J., B.P. Walter, K.A. Masarie, P.M. Lang, and E.S. Kasischke, 2001: Measurements of an anomalous global methane increase during 1998. (pubs.giss.nasa.gov)