Table 2. Global methane emissions by source type in Tg CH4 yr-1 from Kirschke et al. (2013) (left columns) and for this work using bottom-up (middle column) and top-down (right columns). As top-down models cannot fully separate individual processes, only emissions for five categories are provided (see text). Uncertainties are reported as [min–max] range of reported studies. Differences of 1 Tg CH4 yr-1 in the totals can occur due to rounding errors.
Source: Earth System Science Data
URL:     http://www.earth-syst-sci-data.net/8/697/2016/essd-8-697-2016.pdf
(The text for the image(s) on this Web page was taken from the above source.)