Australian Broadcasting Corporation: Methane levels in the atmosphere have started to rise after almost eight years of near-zero growth, an international study says. And the increase may lead to an acceleration of global warming, the scientists behind the study warn. Dr Paul Fraser of the CSIRO, who co-authored the study that appears in Geophysical Research Letters, says samples taken from 12 stations across a global network showed a trend upwards in methane levels. “After seven years [of zero growth] …