Productivity gains will reduce both the need for additional land and the emissions caused by production processes. Without large crop and livestock productivity gains, agricultural land requirement will be orders of magnitude greater by 2050, and greenhouse gas (GHG) emissions could double.
In some mitigation analyses, including reports by the Intergovernmental Panel on Climate Change (IPCC), agricultural productivity gains are barely mentioned, for reasons that are unclear. Even under our baseline projection, with its large increases in crop and livestock yields, the World Resources Institute projects that agricultural land will expand by 593 million hectares to meet expected food demand.
Unless projected growth in demand for food can be moderated, to avoid land expansion both crop yields and pasture-raised livestock yields will have to grow even faster between 2010 and 2050 than they grew in previous decades.
Arguments can be made for both pessimism and optimism:
- Studies have projected that farmers could achieve far higher yields than they do today. However, methods for estimating these “yield gaps” tend to exaggerate gap sizes and farmers can rarely achieve more than 80 percent of yield potential. The most comprehensive study suggests that fully closing realistic yield gaps is unlikely to be enough to meet all food needs.
- The massive yield gains of the 50 years from 1960 to 2010 were achieved in large part by doubling irrigated area and extending the use of scientifically bred seeds and commercial fertilizer to most of the world. Only limited further expansion of these technologies remains possible.
- Optimistically, farmers have so far continued to steadily boost yields by farming smarter in a variety of ways, and new technologies are opening up new potential.
Whatever the degree of optimism, the policy implications are the same: going forward, the world needs to make even greater efforts to boost productivity than in the past to achieve a sustainable food future.
Increasing livestock and pasture productivity
Demand for milk and meat from grazing ruminants (such as cows and sheep) is likely to grow even more than demand for crops. Because pasture makes up two-thirds of all agricultural land, the productivity of livestock will critically affect future land use and emissions.