In the years since the Intergovernmental Panel on Climate Change (IPPC) developed its greenhouse gas accounting rules, one Australian climate scientist says that the world needs a more accurate way to assess what is driving global warming, reports environmental news outlet Plant Based News.
In a peer-reviewed paper published in Environmental Research Letters, Gerard Wedderburn-Bisshop argues that agriculture, particularly livestock farming, is actually the source of most global warming.
His assessment finds that agriculture caused 60 percent of global warming between 1750 and 2020, most of which comes from meat and dairy farming (86 percent), while fossil fuels only accounted for 19 percent of warming during this 270-year period.
Wedderburn-Bisshop, a former Australian government environmental scientist and co-founder of the World Preservation Foundation, is quick to point out that his findings are not meant to let fossil fuels off the hook, stressing the necessity of an urgent shift away from coal, oil and natural gas.
[See more: It is ‘virtually certain’ that Earth has breached the 1.5°C climate change threshold]
However, his analysis adds emphasis to land use, refocusing attention on past and present deforestation in the creation of agricultural land. Knowing the impact of clearing and re-clearing land on carbon emissions, he argues in the paper, “informs policy that destruction of forest of any age could be seen in the same way as burning coal.”
Wedderburn-Bisshop bases his analysis on different greenhouse gas accounting methods. The first is the gross accounting of both fossil carbon and land-clearing carbon. If land use was reported not as a net but as a gross emission, as is the case with all other sectors under IPCC rules, the effect of deforestation would push emissions 2.8 times higher – putting fossil fuels second to land use as a pollution source.
The second measure is to use effective radiative forcing to measure gases, rather than the time-dependent global warming potential (GWP) system presently used by the IPCC, as it is “believed to produce more accurate estimates of climate impact for agriculture.” GWP, Wedderburn-Bisshop points out, “can distort mitigation effectiveness.”
This is in line with the paper’s emphasis on deforestation as a preventable and reversible phenomenon, noting that “restoring forests is commonly recognised as the most effective, lowest cost natural mitigation option.” By giving a clearer accounting of the impact of deforestation, Wedderburn-Bisshop’s analysis aims to “usefully support policy reform.”
