Methane from the House of Tudor and the Ming Dynasty: Anthropogenic emissions in the sixteenth century

Abstract

This paper presents an estimate of global anthropogenic methane (CH 4) emissions during the early modern, pre-industrial, period based on the historical record and current estimates of CH 4 emission factors. Methane emissions are estimated for biomass burning, enteric fermentation and irrigated agriculture. It is concluded that anthropogenic CH 4 emissions were likely to have been at least 55 Tg/CH 4/yr. in 1500 and preceding centuries, contributing to a total annual emissions flux of at least 210 Tg CH 4. At least half of the anthropogenic emissions were likely to have been due to biomass burning, with the remaining from irrigated agriculture and animals. These conclusions suggest that the concentration of OH in the atmosphere may have been greater than today, given that recent deconvolution analysis indicates that a total source strength of only 170 Tg CH 4 a year during the 16th century is consistent with total estimated CH 4 sinks and natural sources at 20th century levels.