By Sophie Wenzlau
The Emissions Gap Report 2013—which involved 44 scientific groups in 17 countries and was coordinated by UNEP—measures the difference between the pledges that countries have made to cut emissions and the targets required to keep global temperature change below 2 degrees Celsius (°C).
The report finds that if the global community does not embark immediately 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 diminish quickly and lead to a host of challenges.
Based on the current trajectory, greenhouse gas emissions in 2020 are likely to reach 8–12 gigatons of carbon dioxide-equivalent (GtCO2e)—roughly comparable to 80 percent of current emissions from the world’s power plants. This is above the level that would provide a likely chance of remaining on the least-cost pathway; to be on track to stay within the 2°C target, emissions should reach a maximum of 44 GtCO2e by 2020, the report says.
Reductions in emissions from agriculture, an often-overlooked source of emissions, could help to close the emissions gap, the 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 emissions because of its heavy requirements for land, water, and energy. The agriculture sector releases more emissions than every car, train, and plane in the global transportation sector.
Activities such as operating 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 greenhouse gas footprint.
UNEP attributes an estimated 38 percent of agricultural emissions 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 UNEP report, certain sustainable agriculture practices present opportunities for dramatically reducing emissions within the sector. Three such practices are especially noteworthy:
1. No-till farming, in which seeds are planted directly under the mulch layer of the previous season’s crop (eliminating the need for ploughing) 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, which can include innovative cropping practices such as alternate wetting and drying and deep placement of urea, resulting in reduced methane and nitrous oxide emissions.
3. Agroforestry, the deliberate use of woody perennials on farms and in landscapes, which can increase the uptake and storage of carbon dioxide from the atmosphere in biomass and soils.
Other practices that can reduce emissions from agriculture include building soil fertility, urban farming, cover cropping, improving water conservation, and preserving biodiversity and indigenous breeds. (For more detail on these, see Worldwatch Report 188, Innovations in Sustainable Agriculture: Supporting Climate-Friendly Food Production.)
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 achieve this goal, the international community must take immediate, concrete steps to reduce emissions across the board.
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. It is an opportunity too good to miss.
Sophie Wenzlau is a senior fellow with the Worldwatch Institute.
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