Date: August 16, 2010
Source: News Room
A new study, funded in part by the Department of Energy (DOE), finds that burning biomass to generate electricity could offset up to 107 billion metric tons of greenhouse gas (GHG) emissions over 100 years, and even greater offsets could be achieved with additional measures involving a biomass fertilizer called "biochar." The new study, "Sustainable Biochar to Mitigate Global Climate Change," published in the journal Nature Communications, contradicts a study by the state of Massachusetts' energy department which argues that burning biomass creates more GHGs than an energy equivalent amount of coal. That report came under broad attack from the biomass industry and others. The new study quantifies the GHG-offset benefits from both burning biomass for electricity and from producing biochar using non-food sources of biomass, such as corn leaves and rice husks. Producing biochar, which involves high-temperature incineration to decompose biomass, would offset annually up to 1.8 billion metric tons of GHG emissions and up to 23 billion metric tons more GHG emissions than biomass energy alone in the first 100 years of production, according to the study. Biochar avoids more GHGs because it can be used as fertilizer to stimulate additional sources of biomass. For comparison, the study notes that human activities produce 15.4 billion metric tons of GHG emissions annually.
Sustainable Biochar to Mitigate Global Climate Change
Dominic Woolf, James E. Amonette, F. Alayne Street-Perrott, Johannes Lehmann & Stephen Joseph
Volume: 1, Article number:56
Received 29 October 2009
Accepted 14 July 2010
Published 10 August 2010
Production of biochar (the carbon (C)-rich solid formed by pyrolysis of biomass) and its storage in soils have been suggested as a means of abating climate change by sequestering carbon, while simultaneously providing energy and increasing crop yields. Substantial uncertainties exist, however, regarding the impact, capacity and sustainability of biochar at the global level. In this paper we estimate the maximum sustainable technical potential of biochar to mitigate climate change. Annual net emissions of carbon dioxide (CO2), methane and nitrous oxide could be reduced by a maximum of 1.8?Pg CO2-C equivalent (CO2-Ce) per year (12% of current anthropogenic CO2-Ce emissions; 1?Pg=1?Gt), and total net emissions over the course of a century by 130?Pg CO2-Ce, without endangering food security, habitat or soil conservation. Biochar has a larger climate-change mitigation potential than combustion of the same sustainably procured biomass for bioenergy, except when fertile soils are amended while coal is the fuel being offset.
To learn more, visit: www.nature.com/ncomms/journal/v1/n5/full/ncomms1053.html.