The agriculture sector’s role in greenhouse gas (GHG) emissions is widely known but not well understood. In truth, more than one-quarter of the world’s GHG emissions come from agriculture, forestry, and land-use change. And unless actively addressed, these emissions are likely to increase as more people populate the Earth and the need for food continues to grow. Our latest report, Agriculture and climate change, looks more deeply at these issues.
Global Warming of 1.5°C, the 2018 report by the Intergovernmental Panel on Climate Change (IPCC), makes clear that a “rapid and far-reaching” transition is required to limit the impact of climate change to 1.5 degrees Celsius.
Doing so would require staying within the cumulative carbon budget of 570 gigatons of equivalent carbon dioxide (GtCO2e),
reaching net-zero carbon dioxide emissions globally around 2050, and significantly reducing the emissions of other gasses—including methane and nitrous oxide. Any successful scenario would mean major changes for agriculture, from how we farm, to how we eat and waste food, to how we manage our forests and natural carbon sinks.
Achieving these major changes may be more challenging for agriculture than for other sectors. Although the pace of emissions reduction remains too slow across the board, other sectors have identified many of the technologies that could substantially reduce emissions: these options don’t necessarily exist in agriculture. Agriculture is also significantly less consolidated than other sectors; reducing emissions requires action by one-quarter of the global population. Finally, the agriculture sector has a complicated set of objectives to consider alongside climate goals, including biodiversity, nutrition need, food security, and the livelihood of farmers and farming communities.
The first step in reducing emissions from agriculture is to produce food as efficiently as possible—that is, to change how we farm. A set of proven GHG-efficient farming technologies and practices—some of which are already being deployed—could achieve about 20 percent of the sector’s required emissions reduction by 2050.
Greenhouse gas–efficient farming practices: The global agriculture marginal abatement cost curve
Building on more than a decade of analysis of GHG abatement, we have identified the top 25 measures to reduce on-farm emissions and organized them into a marginal abatement cost curve (MACC).
These measures have the potential to abate up to a combined 4.6 GtCO2e
by 2050 compared with business-as-usual emissions—a reduction of about 20 percent of total emissions from agriculture, forestry, and land use change. Moreover, the top 15 measures by abatement potential would contribute 85 percent of this emissions abatement and touch four major categories: energy, animal protein, crops, and rice cultivation.
For each measure, a bottom-up assessment of mitigation potential and cost was calculated using a synthesis of available literature; comparison across models of the Global Biosphere Management Model, Common Agricultural Policy Regionalised Impact, and Netherlands Environmental Agency; and discussions with relevant experts and practitioners. Costs shown include capital expenses, operating expenses, and potential cost savings. For all measures, the level of uptake and implementation was assessed to be as ambitious as possible while also being aware of the potential economic and noneconomic barriers to implement across regions, farm scales, and production systems. The interactive below illustrates some of these measures.
This analysis is distinctive in both its breadth and depth; our goal is to provide concrete guidance for policy makers, agriculture players, and academics alike to spur the necessary change in the agriculture sector. Some limitations of the global agriculture MACC should be noted:
- Costs shown are a weighted average and cannot therefore be assumed to apply in all regions.
- Potential overlap is controlled for through constrained adoption at a region and species level as well as limiting the MACC to measures that could feasibly be applied together.
- The MACC could substantially change over the next 30 years because of an increase in both measures and implementation rates.
In the course of human history, agriculture has responded to humanity’s greatest challenges. The sector has increased food production to a level that many believed impossible. The sector now has an opportunity to make yet another major contribution to humanity’s success during this crucial window for action.
Download the full report on which this article is based, Agriculture and climate change (PDF–38MB).