The new UN climate report shows that crop yields already are being adversely affected by a changing climate, and how we respond globally in creating a more resilient food system is very important now. But we also recognize that food is central to our culture and is a source of great pleasure and comfort to people. We want to ensure we tackle all aspects so that we have enough food for the future.
The estimate of more than 9 billion people in less than 40 years highlights a stark challenge for the global food system.
We have enough food for the roughly 7 billion people alive today, but nearly a billion are hungry or malnourished, mostly due to poverty and unequal distribution. To feed those who are currently hungry—and the additional 2 billion-plus people who will live on the planet by 2050—our best projections are that crop production will need to increase between 60 and 100 percent. “Business as usual” could lead to a doubling of demand for agricultural production.
If the population is growing by less than one-third, why would the overall demand double? Simply stated: more people have more money.
Meeting the problem through production alone won’t be enough, and we should explore many alternatives that focus on reducing demand for food, like changing our diets and reducing food waste and loss. Increasing crop production can be part of the solution.
What drives the demand?
Roughly two-thirds of the growing crop-calorie demand will result from growing affluence.
Historically, demand for increased crop production was driven largely by wealthy countries in North America and Europe, and this population will be joined by an additional 3 to 4 billion people already on Earth who are getting wealthier, mostly in India and China. Richer people tend to want richer foods, including meat and dairy products. Adding to the pressure, roughly 9 percent of global crops are currently used to produce biofuels or other industrial products, contributing little to the world’s food supply.
Modern super crops may be part of it, but agriculture can’t be fixed by biotech alone.
Global crop production increased substantially in recent decades. Studies of major crop groups (including cereals, oilseeds, fruits, and vegetables) indicate that production increased by roughly 47 percent between 1985 and 2005.
However, when you consider all 174 crops tracked by the Food and Agriculture Organization, global production increased by about 28 percent over that time period. This was achieved through three kinds of changes:
- Expansion of global croplands: During this period, the area of land in agriculture expanded by 2.4 percent.
- Increase in harvested land: The area of existing croplands harvested grew by 7 percent between 1985 and 2005. This change was due to improvements in multiple cropping, fewer crop failures, and less land left fallow.
- Increased crop yields: After accounting for the changes above, average global crop yields increased by about 20 percent.
Basic math tells us that to double the food supply by 2050 from increased crop production alone, yields will need to increase each year by roughly 2.4 percent of 2007 yields.
Further expansion of agriculture is a poor solution to meeting future needs because we’re using nearly all of the land that’s suitable for agriculture already. Relying on increased production alone will be an important solution, but not a sufficient one, whether through increased yields or harvest frequency. Doubling crop production would require clearing ~1 billion hectares of land—mostly rainforests, which would create havoc with the carbon dioxide absorption needed to deal with global warming.
We can address at least part of the problem by growing more crops, but meeting the world’s needs by mid-century will require as much attention to our diets, reducing food waste, and improving food security worldwide.
The cost of expanding our footprint
If the world meets future crop demand as it has in the past, countries with low crop yields would increase production through clearing more agricultural land (expansion), while more wealthy nations with high yields would increase production through growing more crops on their existing agricultural land (intensification).
This approach to doubling food production by 2050 would require:
150 megatons (150 x 106 tons) of nitrogen—the extra amount we would need to apply each year on top of what we already use—is more than 6 times the total amount of nitrogen fertilizer applied each year in China. And it’s almost 12 times the amount of nitrogen that U.S. farmers use annually.
Meanwhile, a 2-gigaton (2 x 109 tons) rise in yearly CO2 equivalents would be greater than the annual emissions from every car, train, and plane in America.
We simply can’t afford to double food production this way. It would drive many animal species to extinction, raise greenhouse gas levels, compromise ecosystems, and pollute our waters.
Future demand vs. Current trends
In the next four decades, crop production will need to grow by 60 to 100 percent from 2005 levels, depending on assumptions. But the yields of major world crops are not rising fast enough to meet that demand.
Based on current crop yields, researchers suggest production could be boosted by roughly 67 percent for maize, 42 percent for rice, 38 percent for wheat, and 55 percent for soybeans.
Widespread stagnation of yields
Presenting yet another challenge, some yields for many of our most important crops are stagnating. Just four crops—maize, rice, wheat, and soybeans—provide two-thirds of the calories we harvest from fields. In many parts of the world, the yields for these crops are not rising.
A host of environmental and political forces are driving this widespread stagnation. In Southern Africa, Eastern Europe, and throughout much of Asia, a lack of fertilizer or irrigation water limits crops. In Africa, socioeconomic factors are the biggest driver. In Asia and Australia, factors including heat stress, high night temperatures, depleted soils, erosion, and disease contribute to a lack of yield growth. Additional challenges include competition for irrigation water and a lack of capital for other inputs.
In many places, boosting yields will require a mix of strategies beyond better supply of irrigation water and fertilizer, such as improved seed varieties, rebuilding degraded soils, and pest and weed control.
Key areas where production could be increased, bringing yields closer to their potential, include wheat in Eastern Europe and Central Asia, rice in South Asia, and maize in East Asia. In sub-Saharan Africa, yields of cassava, maize, and sugarcane could also be greatly improved.
Altogether, these trends mean we won’t be able to double crop production by 2050 through business-as-usual yield growth alone.
Just four crops—maize, rice, wheat, and soybeans—provide two-thirds of the calories we harvest from fields.
Based on the period between 1999 and 2008, both rice and wheat yields are languishing on more than one-third of the world’s harvested croplands.
In Asia, where most rice is grown, yields are stagnating across most of China and Indonesia’s rice-growing areas, and on about a third of rice croplands in India.
Nearly all of the breadbaskets of Western and Eastern Europe now have stagnating wheat yields, as do most wheat croplands in India and more than half of wheat-growing areas in Turkey and China.
In the United States, yields are flat in more than one-quarter of all wheat areas, mostly in the Great Plains region. While there is a greater proportion of maize and soybean areas where yields are improving, yields are stagnating in one-quarter to one-third of harvested areas for both of these crops as well.
AREAS FOR IMPROVEMENT
How, then, will we close the gap between future food production and demand?
Experts observe large variation in yields around the world, even in areas with similar growing conditions. We could boost yields on under performing lands by improving nutrient and water supplies to crops.
Helping farmers boost yields to within 75 percent of yields attained by top-performing farmers facing similar growing conditions would be enough to meet the basic calorie needs for about 2.8 billion people (eating a 2,700 calorie diet per day).
In many parts of the world, we must address problems with distribution, access to appropriate seed varieties, and market infrastructure.
Another way to reduce the gap is to better use the crops we already grow. Changing our diets to depend less on rich foods, especially ruminant meat, and curbing food waste, can reduce global demand for food. If fully embraced, these changes could have profound effects. Even smaller steps in this direction could have a significant impact.
To successfully close the gap, we’ll need to adopt a variety of innovative strategies. We must produce more crops, while more efficiently using the food we already grow.
The good news? Many solutions are already here.
Credits: Barrett Colombo, Peder Engstrom, Deepak Ray, Andrew Urevig, Paul West. Design: smashLAB. Published by the Institute on the Environment at the University of Minnesota
Agroforestry could help solve Climate Change.
HELPING SOLVE WORLD’S CARBON POLLUTION
- New Trees are the only solution to soaking up Carbon Dioxide:
A Full Scale Aquaponic Tree Nursery in Africa supported by:
- A Micro Hydro Electric System: no dams: HugENERGY.us
- An Irrigation System: NORTHydro.com
- A Rabbit and Fish Farm: AfriCAPITALISM.us
- An Agroforestry Intercrop System: LivingWaterIs.com
- The Charitable Arm: SunnyUp.net
- God’s Loveletters: Godloveletters.com
- Thunder of Justice: ThunderofJustice.com
- Deliverance Is: DeliveranceIs.com