August 1, 2018.
Understanding biomass burning is important for understanding atmospheric carbon budgets. The two main types of biomass burning are wildfires, and the burning of traditional biofuels. Both types of biomass burning produce methane, among other gases. Satellites in space help quantify area burned from wildfires. However, it is much more difficult to quantify the burning of traditional biofuels, such as animal waste, fuelwood, charcoal, crop material, and peat. Therefore, limited information is available regarding these process, and how they contribute to human caused climate change. Here, we have developed a global inventory of methane emissions from the burning of traditional biofuels over a 15 year time span. Using information from the UN Energy Statistics Database, a global upper estimate of annual methane emissions from this type of biomass burning was calculated for the years 2001-2015. The equation had three components: the final energy consumption of each of the considered sources, in each country, for each year; the relative smoldering or flaming of that material when burned; and the emission factor for methane gas specific to each material. Results show it is evident that on a global scale, methane emissions from the burning of traditional biofuels are increasing over this time span. In fact, the upper estimate calculated suggests a 17.5% increase in global methane emissions from 2001-2015 from this type of biomass burning. Charcoal production and consumption are leading these increases, specifically in tropical regions. By 2015, the estimate suggests 17.5 Tg of methane is being emitted from the burning of traditional biofuels. Thus, methane emissions from burning traditional biofuels are not negligible when evaluating the global methane budget. This information is crucial when assessing methane emissions from other sources such as microbial sources and fossil fuels.
National Oceanic Atmospheric Administration Earth Systems Research Laboratory (NOAA ESRL)
The 2018 STEM Teacher and Researcher Program and this project have been made possible through support from Chevron (www.chevron.com), the National Marine Sanctuary Foundation (www.marinesanctuary.org), the National Science Foundation through the Robert Noyce Program under Grant #1836335 and 1340110, the California State University Office of the Chancellor, and California Polytechnic State University in partnership with NOAA ESRL. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funders.