Scientists have calculated, for the first time, the extent to which agricultural emissions must be reduced to limit warming to 2°C in 2100. And, they propose a 1 gigatonne annual reduction target by 2030 for farming, arguing that current interventions to reduce emissions in agriculture could only achieve 21-40% of this goal.
This post is adapted from the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) blog.
The analysis outlines how agriculture can mitigate climate change through carbon sequestration, as well as reducing non-carbon dioxide emissions such as methane and nitrous oxide – both potent greenhouse gases with significantly higher global warming potential than carbon dioxide (CO2).
Current interventions are not enough
Although 119 nations included mitigation in agriculture in their Intended Nationally Determined Contributions submitted to the UNFCCC, no work has been carried out to determine how these pledges will be met.
To meet them, authors from various CGIAR centres including the International Center for Tropical Agriculture (CIAT), and partner institutions urge that the agriculture sector must reduce non-CO2 emissions by 1 gigatonne – or 1,000,000,000 tonnes per year – by 2030.
“This research is a reality check,” said Lini Wollenberg, leader of the CCAFS Low Emissions Development research program, based at the University of Vermont’s Gund Institute for Ecological Economics.
“Countries want to take action on agriculture, but the options currently on offer won’t make the dent in emissions needed to meet global targets agreed to in Paris. We need a much bigger menu of technical and policy solutions, with major investment to bring them to scale.”
Meeting the target
To realize the 1 gigatonne annual reduction target for non-CO2 emissions in agriculture set out in the paper, 21-40% of mitigation could be achieved with practices such as:
- Sustainable intensification of cattle
- Efficient use of water through alternate wetting and drying in irrigated rice
- Nutrient management for annual crops, including efficient use of nitrogen and manure
- Relocating production to increase input efficiency
But implementation would require massive investment, information sharing and technical support to enable a global-scale transition. Much higher impact technologies and policies will be needed as well, say authors.
Sequestering carbon in soils could further contribute to meeting the mitigation target, and thus has been included in the analysis. However, “even the best practices we know of now for sequestering carbon in the soil are not good enough to meet these targets”, says Dr. Rolf Sommer, the leader of CIAT’s soil health program.
“If we are realistic about sequestering more carbon in the soil – we need to come up with new options. What we have in our arsenal right now is not enough.”
Livestock fodder options for mitigation
Promising technical innovations on the horizon include recently developed methane inhibitors that reduce dairy cow emissions by 30% without affecting milk yields, varieties of cereal crops that release less nitrous oxide.
Or, fodder grass species like Brachiaria that haven been proven to sequester significantly higher amounts of carbon in the soil than what has been observed in annual cropping systems so far, while at the same time reducing nitrous oxide emissions through the release of biological nitrification inhibitors (BNI) into the soil.
In addition to sequestering carbon in soils, focusing more attention to increasing agroforestry, decreasing food loss and waste and shifting dietary patterns could all significantly reduce emissions from agriculture, say authors.
Agriculture, not including land use change, contributes an average of 35% of emissions in developing countries and 12% in developed countries today. But, authors warn, efforts to mitigate emissions levels must be balanced with countries’ need to produce enough food – and cannot come at the cost of food security.
“Reducing emissions from agriculture to meet the 2°C target” was first published in Global Change Biology on 17th May 2016.
For more information:
- Agriculture’s prominence in the INDCs
- Agriculture’s contribution to national emissions
- Mitigation Options Tool for Agriculture
- Potentials for soil organic carbon sequestration vary from place to place and over time. Investment is needed to gather more reliable soil data and to develop decision support tools for making place-specific recommendations.
- For agriculture to contribute to the mitigation of climate change, as opposed to accelerating climate change, best-bet agricultural management practices need a fundamental overhaul, including exploring trade-offs between boosting production, lowering emissions and increasing soil carbon.
- Forage options which increase milk and meat production but also lower emission intensities from cattle, sequester carbon in the soils and reduce nitrous oxide emissions, need to be further researched and mainstreamed.
This research is carried out with support from CGIAR Fund Donors and through bilateral funding agreements. The authors gratefully acknowledge funding from: Australia (ACIAR); Denmark (DANIDA); Ireland (Irish Aid); Netherlands (Ministry of Foreign Affairs); New Zealand Ministry of Foreign Affairs &Trade; Portugal (IICT); Russia (Ministry of Finance); Switzerland (SDC); The UK Government (UK Aid); The European Union (EU); The Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ);The Program is carried out with technical support from The International Fund for Agricultural Development (IFAD).