Beef often gets a bad rap as far as climate change is concerned. It has been described as the ‘Hummer of food’ because while it represents just 30 percent of meat consumption in richer countries, it produces 78 percent of the greenhouse gas (GHG) emissions from the livestock sector.
The bulk of those emissions are from cows belching out methane, a powerful greenhouse gas, and from fertilizer, from manure, and from transporting the animals. But emissions also come from the transformation of rainforest into grazing land. Some four fifths of Amazonian deforestation that has occurred since the 1960s was performed to provide pastureland for farm animals, primarily cattle.
The first, appearing in Nature Climate Change, notes that since 2005, beef production has expanded while emissions from the sector have declined. The paper in part links the trend to Brazil’s successful crack down on the razing of forest for agricultural production.
The only way to service the growing demand for meat in the face of restrictions on land use has been to ramp up productivity—also known as “”sustainable intensification”. The concept applied to the Brazilian beef sector involves better management of grasslands and pasture restoration through mechanical and chemical treatment of the soil.
This in turn boosts the uptake of carbon by grasses and raises the stock of carbon stored in the soil. The researchers modelled what would happen should demand for beef decline, and found that the incentive for improved pasture management dissipates. In turn, grasslands deteriorate, organic matter is lost and soil carbon stocks are reduced. However the good news does have an upper limit. The scientists ran their model up to 2130 and found that increases in demand for beef drives decreases in emissions only until 2057. At which point, the situation reverses, and the grassland sequestration of carbon no longer offsets emissions from the increased animal numbers.
The Brazilian findings echo those of an Agriculture Canada study also out in January and appearing in Animal Production Sciencethat found GHG emissions from Canada’s beef sector declined 15 percent per kilogram of beef from 1981-2011.
The result largely comes from farmers increasing the kilograms of meat delivered per hectare via improving the growth rate of calves, genetics and better nutrition. Other improvements include upgraded reproductive efficiency—decreasing the number of cows needed to produce the same number of calves—higher quality forage, and enhanced grass management, permitting more carbon sequestration.
Eagle-eyed readers may note that while the Brazilian researchers declared themselves to have no financial conflicts of interest, the Canadian study was part-funded by the industry-financed Beef Cattle Research Council. One of the authors, veterinary science specialist Tim McAllister, told the Scan that his employer is the government of Canada, not cattle ranchers.
“When we started this work, we were completely unaware of what the outcome would be and were prepared to publish and report the findings regardless of that outcome,” he said.
The Climate Examiner speaks to BC-based Carbon Engineering about the technology, the business and the policies that could make direct air capture, synfuels and carbon sequestration work.