By Sophie Wenzlau
Reductions in emissions from agriculture could help to close the greenhouse gas emissions gap. (Photo Credit: ucanr.edu)
The Emissions Gap Report 2013—which involved 44 scientific groups in 17 countries and was coordinated by UNEP—measures the difference between the pledges countries have made to cut emissions and the targets required to keep global temperature change below 2°C.
The report finds that if the global community does not immediately embark on wide-ranging actions to narrow the greenhouse emissions gap, the chance of remaining on the least-cost path to keeping global temperature rise below 2°C this century will quickly diminish.
Based on the current trajectory, greenhouse gas emissions in 2020 are likely to be 8 to 12 gigatons of CO2 equivalent (GtCO2e)—roughly comparable to 80 percent of current emissions from the world’s power plants—above the level that would provide a likely chance of remaining on the least-cost pathway.
Reductions in emissions from agriculture, an often-overlooked emissions producing sector, could help to close the emissions gap, report authors say. They estimate that emission-reduction potentials for the sector range from 1.1 GtCO2e to 4.3 GtCO2e.
Worldwide, agriculture contributes between 14 and 30 percent of human-caused greenhouse gas (GHG) emissions because of its heavy land, water, and energy use—that’s more than every car, train, and plane in the global transportation sector.
Activities like running fuel-powered farm equipment, pumping water for irrigation, raising dense populations of livestock in indoor facilities, managing soils, and applying nitrogen-rich fertilizers all contribute to agriculture’s high GHG footprint.
The UNEP estimates that 38 percent of agricultural emissions can be attributed to nitrous oxide from soils, 32 percent to methane from enteric fermentation in ruminant livestock, 12 percent to biomass burning, 11 percent to rice production, and 7 percent to manure management. Direct agricultural emissions account for 60 percent of global nitrous oxide emissions and 50 percent of global methane emissions, according to the report.
According to the Emissions Report, certain sustainable agriculture practices present opportunities for dramatic emissions reductions within the sector. The report identifies three such practices as especially noteworthy.
1. No-till farming, in which seeds are planted directly under the mulch layer of the previous season’s crop and the need for ploughing eliminated, can reduce emissions associated with soil disturbance and the use of fossil-fuel powered farm machinery.
2. Improved nutrient and water management in rice production can include innovative cropping practices such as alternate wetting and drying and urea deep placement, which can reduce methane and nitrous oxide emissions.
3. Agroforestry, the deliberate use of woody perennials on farms and in landscapes, can increase the uptake and storage of carbon dioxide from the atmosphere in biomass and soils.
Other practices that can reduce emissions from agriculture—practices discussed in detail in Worldwatch Report 188, Innovations in Sustainable Agriculture: Supporting Climate-Friendly Food Production—include building soil fertility, urban farming, cover cropping, improving water conservation, and preserving biodiversity and indigenous breeds.
The adoption of climate-friendly agriculture practices not only contributes to climate-change mitigation, but also enhances the sector’s environmental sustainability. In the long-term, these practices can provide other benefits such as higher yields, lower fertilizer costs, and increased profits.
Meeting the 2020 emissions reduction goal is still possible, but the window of opportunity is narrowing. To meet this goal, the international community must take immediate, concrete steps to reduce emissions across the board, including agriculture.
By tapping into the multitude of climate-friendly farming practices that already exist, agriculture can continue to provide food for the world’s population, remain a source of livelihood for the 1.3 billion people who rely on farming for income and sustenance, help to mitigate greenhouse gas emissions, and increase resiliency to the climate change that is already in motion.
Sophie Wenzlau is a senior fellow with the Worldwatch Institute.