Farming could be absorber of carbon by 2050, says report
If one in five people in richer countries went near-vegan, and threw away a third less food than they currently do, while poor countries were assisted to preserve their forests and restore degraded land, the world’s agricultural systems could be absorbing carbon dioxide by 2050 instead of adding massively to global heating as they do at present.
Tree-planting and improving the fertility of soil through better farming practices would also be needed, according to a study of global forests, farming and food systems published in the journal Nature Climate Change.
Managing agricultural and other land in a more environmentally sound manner could take the world nearly a third of the way towards meeting the Paris agreement goals. “These [measures] are feasible now and deliver many other benefits,” said Stephanie Roe, environmental scientist at the University of Virginia and lead author of the paper.
“Recent reports on the state of our forests and food systems show a worrying lack of progress in the land sector, and our window of opportunity to deliver on the Paris agreement is getting smaller. However, I remain optimistic because we have all the tools we need, as well as increasing public pressure and political will to turn things around.”
The changes would also allow for healthier diets globally, improve livelihoods in poor areas, preserve wildlife and flora, and make for higher water and air quality. Many of the measures suggested, such as cutting food waste and shifting from excessive meat consumption, would also save money. For example, improving soil management through organic farming practices would cost about $57bn (£43.9bn) but save nearly $2tn over the period, according to one estimate used in the study.
Land accounts for about 25% of global greenhouse gas emissions, or 11 gigatons of carbon dioxide a year. With the right measures, according to the study, it would act instead as a carbon sink absorbing 3 gigatons from the atmosphere a year by 2050. That could give some scope for other sectors such as aviation to continue to use limited amounts of fossil fuels while staying within the global carbon budget needed to avoid a temperature rise of more than 1.5C (a rise of 2.7F) above preindustrial levels.
The authors set out a roadmap for the six large-scale measures they propose, including: reducing deforestation, peatland burning and mangrove destruction by 70%; restoring forests, peatlands and coastal mangroves to generate enough carbon dioxide saving to cancel out China’s annual emissions; planting trees to save as much carbon dioxide as that emitted by the EU.
Improving farming practices, including moving to more organic practices, would mean better soil management that could cut carbon dioxide equal to India’s annual emissions. Consumer food waste in rich countries and big developing countries could be cut by a third, while the losses from food production in poor regions such as sub-Saharan Africa and south-east Asia could be cut drastically through simple measures such as more refrigeration and better transport. Moving a fifth of people to plant-based diets in developed and emerging countries, particularly the US, the EU, China, Brazil, Argentina and Russia, is seen as possible by 2030. These near-vegan diets would involve consuming less than 2,500 calories a day and no more than 60g of animal protein.
Prof Thomas Crowther, founder of the Crowther Lab, who was not involved with the study, said: “This is an excellent review of the many carbon drawdown solutions that the land can provide. There are immense benefits of restoring natural ecosystems like forests, wetlands and peatlands. Managed ecosystems can also be critical through effective agroforestry, biochar techniques and regenerative agriculture that can increase soil carbon sequestration. The review also reveals the considerable uncertainty and challenges that we face in realising this carbon drawdown potential, highlighting the need for more quantitative research into the scale and dynamics of carbon storage on land.”
Developing nations are hoping that the forthcoming UN meeting on the climate emergency, COP25 in Santiago, will encourage rich countries to focus on helping them cut emissions through better land use and management of the oceans. A spokesperson for the UK’s Department for International Development said: “Cutting carbon emissions by helping developing countries change how they use and farm land is a priority for UK aid. We are fighting illegal deforestation and supporting poor farmers to make their practices greener. By making farming practices more efficient, we reduce the amount of land needed to produce food.”
Nancy Harris of the World Resources Institute, a co-author of the study, said: “The longer we delay action to protect forests, the more difficult it will be to achieve the Paris agreement targets and the more we will need to rely on unproven negative emission technologies.”