In a paper published in National Science Review, an international team of scientists evaluated scenarios about what is causing methane concentrations to rapidly increase in the atmosphere. By combining new and novel isotopic datasets on methane source signatures with simple atmospheric models, they ran thousands of potential emission pathways and isolated those that best matched the observed change of methane isotopes in the atmosphere. Using this approach, the authors found that the methane sources most likely driving the increase are from human activities, including agriculture, landfills and waste management, and from the use of coal, oil and gas. These activities are responsible for more than 80 percent of the rise of atmospheric methane since 2007. The analysis suggests that wetland emissions have not contributed significantly to increases in atmospheric methane, despite continued warming and climate extremes.