Executive Summary (Synthesis)
Executive Summary (Synthesis)
As the global population grows from 7 billion in 2010 to a projected 9.8 billion in 2050, and incomes grow across the developing world, overall food demand is on course to increase by more than 50 percent, and demand for animal-based foods by nearly 70 percent. Yet today, hundreds of millions of people remain hungry, agriculture already uses almost half of the world’s vegetated land, and agriculture and related land-use change generate one-quarter of annual greenhouse gas (GHG) emissions.
This synthesis report proposes a menu of options that could allow the world to achieve a sustainable food future by meeting growing demands for food, avoiding deforestation, and reforesting or restoring abandoned and unproductive land—and in ways that help stabilize the climate, promote economic development, and reduce poverty.
Achieving these goals requires closing three great “gaps” by 2050:
- The food gap—the difference between the amount of food produced in 2010 and the amount necessary to meet likely demand in 2050. We estimate this gap to be 7,400 trillion calories, or 56 percent more crop calories than were produced in 2010.
- The land gap—the difference between global agricultural land area in 2010 and the area required in 2050 even if crop and pasture yields continue to grow at past rates. We estimate this gap to be 593 million hectares (Mha), an area nearly twice the size of India.
- The GHG mitigation gap—the difference between the annual GHG emissions likely from agriculture and land-use change in 2050, which we estimate to be 15 gigatons of carbon dioxide equivalent (Gt CO2e), and a target of 4 Gt that represents agriculture’s proportional contribution to holding global warming below 2°C above pre-industrial temperatures. We therefore estimate this gap to be 11 Gt. Holding warming below a 1.5°C increase would require meeting the 4 Gt target plus reforesting hundreds of millions of hectares of liberated agricultural land.
This report explores a 22-item “menu for a sustainable food future,” which is divided into five “courses” that together could close these gaps: (1) reduce growth in demand for food and agricultural products; (2) increase food production without expanding agricultural land; (3) exploit reduced demand on agricultural land to protect and restore forests, savannas, and peatlands; (4) increase fish supply through improved wild fisheries management and aquaculture; and (5) reduce greenhouse gas emissions from agricultural production.
On the one hand, the challenge of simultaneously closing these three gaps is harder than often recognized. Some prior analyses overestimate potential crop yield growth, underestimate or even ignore the challenge of pastureland expansion, and “double count” land by assuming that land is available for reforestation or bioenergy without accounting for the world’s growing need to produce more food, protect biodiversity, and maintain existing carbon storage. Significant progress in all 22 menu items is necessary to close the three gaps, requiring action by many millions of farmers, businesses, consumers, and all governments.
On the other hand, the scope of potential solutions is often underestimated. Prior analyses have generally not focused on the promising opportunities for technological innovation and have often underestimated the large social, economic, and environmental cobenefits. Our menu is detailed but several themes stand out:
- Raise productivity. Increased efficiency of natural resource use is the single most important step toward meeting both food production and environmental goals. This means increasing crop yields at higher than historical (linear) rates, and dramatically increasing output of milk and meat per hectare of pasture, per animal—particularly cattle—and per kilogram of fertilizer. If today’s levels of production efficiency were to remain constant through 2050, then feeding the planet would entail clearing most of the world’s remaining forests, wiping out thousands more species, and releasing enough GHG emissions to exceed the 1.5°C and 2°C warming targets enshrined in the Paris Agreement—even if emissions from all other human activities were entirely eliminated.
- Manage demand. Closing the food gap will be far more difficult if we cannot slow the rate of growth in demand. Slowing demand growth requires reducing food loss and waste, shifting the diets of high meat consumers toward plant-based foods, avoiding any further expansion of biofuel production, and improving women’s access to education and healthcare in Africa to accelerate voluntary reductions in fertility levels.
- Link agricultural intensification with natural ecosystems protection. Agricultural land area is not merely expanding but shifting from one region to another (e.g., from temperate areas to the tropics) and within regions. The resulting land-use changes increase GHG emissions and loss of biodiversity. To ensure that food production is increased through yield growth (intensification) and not expansion, and productivity gains do not encourage more shifting, governments must explicitly link efforts to boost crop and pasture yields with legal protection of forests, savannas, and peatlands from conversion to agriculture.
- Moderate ruminant meat consumption. Ruminant livestock (cattle, sheep, and goats) use two-thirds of global agricultural land and contribute roughly half of agriculture’s production-related emissions. Ruminant meat demand is projected to grow by 88 percent between 2010 and 2050. Yet, even in the United States, ruminant meats (mostly beef) provide only 3 percent of calories. Closing the land and GHG mitigation gaps requires that, by 2050, the 20 percent of the world’s population who would otherwise be high ruminant-meat consumers reduce their average consumption by 40 percent relative to their consumption in 2010.
- Target reforestation and peatland restoration. Rewetting lightly farmed, drained peatlands that occupy only around 0.3 percent of global agricultural lands provides a necessary and cost-effective step toward climate change mitigation, as does reforesting some marginal and hard-to-improve grazing land. Reforestation at a scale necessary to hold temperature rise below 1.5 degrees Celsius (i.e., hundreds of millions of hectares) is potentially achievable but only if the world succeeds in reducing projected growth in demand for resource-intensive agricultural products and boosting crop and livestock yields.
- Require production-related climate mitigation. Management measures exist to significantly reduce GHG emissions from agricultural production sources, particularly enteric fermentation by ruminants, manure, nitrogen fertilizers, and energy use. These measures require a variety of incentives and regulations, deployed at scale. Implementation will require far more detailed analysis and tracking of agricultural production systems within countries.
- Spur technological innovation. Fully closing the gaps requires many innovations. Fortunately, researchers have demonstrated good potential in every necessary area. Opportunities include crop traits or additives that reduce methane emissions from rice and cattle, improved fertilizer forms and crop properties that reduce nitrogen runoff, solar-based processes for making fertilizers, organic sprays that preserve fresh food for longer periods, and plant-based beef substitutes. A revolution in molecular biology opens up new opportunities for crop breeding. Progress at the necessary scale requires large increases in R&D funding, and flexible regulations that encourage private industry to develop and market new technologies.
Using a new model called GlobAgri-WRR, we estimate how three scenarios we call “Coordinated Effort,” “Highly Ambitious,” and “Breakthrough Technologies” can narrow and ultimately fully close our three gaps. Figure ES-1 illustrates how our five courses of action could feed the world and hold down global temperature rise. Although a formidable challenge, a sustainable food future is achievable if governments, the private sector, and civil society act quickly, creatively, and with conviction.
Figure ES-1 |
Ambitious efforts across all menu items will be necessary to feed 10 billion people while keeping global temperature rise well below 2 degrees Celsius
These charts show the most ambitious “Breakthrough Technologies” scenario. “Restore forests and peatlands” item includes full reforestation of at least 80 million hectares of liberated agricultural land, in order to reach the 4 Gt CO2 e/year target by 2050 for limiting global temperature rise to 2°C. As an even more ambitious option, in order to limit warming to 1.5°C, full reforestation of at least 585 million hectares of liberated agricultural land could offset global agricultural production emissions for many years.