Photo: Flickr.com /Claire Backhouse CC BY-ND
Achieving a sustainable food future
Feeding the world while staying below 1.5°C by 2050 will require increased productivity, shifts in consumption, new technology and massive reforestation, according to a new report.
In July, the World Resource Institute published the report “Creating a Sustainable Food Future”, in which it takes a broad look at how we can sustainably feed nearly ten billion people on Earth by 2050. The report recognizes three “gaps” that must be closed by 2050 to achieve this:
- A 56-percent “food gap” between what was produced in 2010 and the food that will be needed in 2050;
- A nearly 600-million-hectare “land gap” (an area nearly twice the size of India) between global agricultural land area in 2010 and expected agricultural expansion by 2050; and
- An 11-gigaton “greenhouse gas mitigation gap” between expected emissions from agriculture in 2050 and the level needed to meet the Paris Agreement.
These targets assume a baseline from which crop productivity continues to grow at the same rate as during the period 1961–2010. With no production gains after 2010 the agricultural area would expand by 3.2 billion hectares, which according to the report would mean the elimination of “the majority of the world’s remaining forests and woody savannas”.
The bridge to a sustainable food system is presented in the form of 22 “menu items”. They cover diverse areas of action ranging from reduced food waste, dietary shifts, limited fertility rates, increased carbon sequestration, further improvements in productivity and new technologies that inhibit enteric fermentation. The potential of each menu item is assessed quantitatively and based on what would be required in the form of institutional coordination and technical breakthroughs.
Only the most ambitious scenario (see figure) will be enough to hold global warming below 1.5°C, that includes the full implementation of all items on the list, plus reforesting more than 585 million hectares (an area greater than the European Union) made available by these demand- and supply-side efficiency gains.
“Millions of farmers, companies, consumers and every government on the planet will have to make changes to meet the global food challenge. At every level, the food system must be linked to climate strategies as well as ecosystem protection and economic prosperity,” said Andrew Steer, President and CEO of the World Resources Institute.
Historical productivity gains have been achieved through the introduction of artificial fertilizers, pesticides and irrigation, e.g. the green revolution in Asia in the 1960s. To do this everywhere is no longer possible or consistent with environmental goals. The authors instead believe that “advances in molecular biology and related breeding technologies offer great potential for boosting productivity above trend lines”. They also stress the need to improve the productivity of pastureland: “every hectare of global pasture that is capable of and appropriate for sustainable intensification must be fully exploited to realize its potential to increase milk or meat output several times over”.
On the demand side, dietary shift is the menu item with most effect on greenhouse gas emissions. Reducing the consumption of ruminant meat by 30 percent globally, compared to the 2050 baseline, would reduce emissions by more than 5 Gt. Targeting ruminant meat is also considered to be effective as “relatively few people eat large quantities of ruminant meat, there are highly attractive alternatives to ruminant meat, and people in the United States and Europe have already reduced per capita beef consumption by one-third from peak levels in the 1970s”.
Action to reduce food loss and waste is also important to curb demand, though challenging. There are not many successful examples that have achieved reductions on a larger scale to learn from. The report explains a dilemma “as countries’ economies develop, waste near the consumption side of the food supply chain tends to grow even as food loss near the production side decreases”. The share of food that is lost or wasted tends to stay the same although the sources of the loss and waste shift downstream.
Limiting population growth is another key to limit demand on agricultural products. The aim is to achieve replacement level fertility rates globally – typically around 2.1 children per woman. North America and Europe are already below replacement level. Asia, Latin America, and Oceania are just above. North Africa’s fertility rate is expected to drop to 2.4 children per woman by 2050. The exception is sub-Saharan Africa, where fertility rates are expected to drop from 5.1 to around 3.2 children per woman by 2050, in other words well over replacement level. The authors of the report believe that with targeted and coordinated efforts in the region, such as increased educational opportunities for girls, increased access to reproductive health services, and reduced infant and child mortality, it would be possible to reach replacement levels by 2050. Especially since this has been done in other regions over a similar time period.
Productivity gains and reduced demand that will limit agricultural expansion must also be accompanied by the protection of forests, savannas and wetlands. Restoring peatlands is identified as an especially promising mitigation opportunity since “emissions of more than 1 Gt CO2e per year result from only 26 million ha, half of which has limited agricultural use”. To reduce agricultural emissions to 4 Gt by 2050, which is in accordance with achieving the Paris agreement, reforestation of at least 80 million ha would be necessary. Though, as mentioned previously, to limit global warming to below 1.5°C a further 505 million ha would need to be reforested.
The report also includes technical measures to reduce greenhouse gas emissions from farming. Recent progress in feed additives suggests the potential for 30 per cent reductions in methane emissions from cattle. At present this does however require that cattle that can be fed additives daily, excluding most grazing cattle. For rice cultivation there are alternative management practices and new strains that reduce methane emissions from the sector by 10 per cent. A combination of better general nitrogen management, technologies such as nitrogen inhibitors and crop breeding to enhance nitrogen use efficiency, could possibly increase global nitrogen use efficiency by 67 per cent. This would lead to reduced nitrous oxide emissions and lowered demand for artificial nitrogen fertilizers. The most ambitious scenario includes technologies that have not yet been developed, but where the authors have assessed that breakthroughs would be possible if the right types of investments are made.
Despite the challenges the report paints, Achim Steiner, Administrator of UN Development Programme, holds on to an optimistic perspective “It’s possible to produce more food on the same amount of agricultural land as today, protect ecosystems, and do this in a manner that ensures farmers and others can prosper. Creating a sustainable food future won’t be easy – but it can be done.”
“Creating a Sustainable Food Future”, published by the World Resource Institute in July 2019, https://wrr-food.wri.org/sites/default/files/2019-07/WRR_Food_Full_Repor...
Press release 16 July 2019, https://www.wri.org/news/2019/07/release-new-research-outlines-5-course-...
Figure. The emissions mitigation gap can be bridged by the most ambitious scenario.
Note: “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 CO2e/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.