Man-made methane emissions back to the Roman period.
© 2012 EPFL
Natural and anthropogenic variations in methane sources during the past two millennia.
"Prof. Jed Kaplan’s lab (Atmosphere Regolith Vegetation - ARVE) provided a global reconstruction of human land-use over the past two millennia, allowing the researchers to detangle human from natural greenhouse gas emissions. While one might naïvely assume that the pre-industrial human contribution to methane emissions was negligible on a global scale, Kaplan’s calculations show that 20 to 30 per cent of methane emitted from fires between 100 BC and 1600 AD is of human origin. The study published in Nature produced a time-line of atmospheric methane composition in unprecedented high resolution. When plotted as a graph it reveals troughs and peaks that previous studies had overlooked. One thing that is certain, is that human activities since the industrial revolution have added a new, very prominent peak in methane concentrations to Greenland’s glaciers for future generations to study. If, that is, the glaciers are still around then."