This is the second in a series of posts related to the Royal Society’s recently published issue “Food Security: Feeding the World in 2050,” which focuses on the drivers of change in the global food system and the challenges it faces to 2050.
According to a recent article in the Royal Society’s journal Philosophical Transactions B, agricultural areas that typically experience extreme weather events every “one in 20” years will see an average rise in temperature of 3 degrees Celsius (4.8 ˚F) by 2050. And most places “will be hotter by 1 to 3˚ C.” This could increase the intensity of drought or floods and their effects on agricultural production. But the several articles that discuss climate change provide no firm conclusion on the effects of changing temperatures on crop yields and resource availability in different countries.
For arable crops, yields would increase in higher latitudes where growing seasons are prolonged, and decrease in lower latitudes where plants become stressed during times of flowering due to higher temperatures. According to some researchers, the increase in atmospheric greenhouse gases could actually provide a favorable climate for crops such as wheat, rice soya, and potato, but not for maize or sorghum. In an optimistic scenario, climate change could also reduce water needs for rain-fed crops, resulting in higher yields. But the changes in rainfall patterns and rising temperatures may also lead to increased evaporation, decreasing water availability; according to studies, an estimated 10-percent increase in precipitation would be required to balance an increase in temperature of 4˚C (5.6˚F).
Moreover, a predicted increase in industrial ozone emissions of 20 to 25 percent by 2050 could negatively affect crop growth, offsetting potential yield increases. Some authors point to the need for more studies to determine the real level of yield gaps for staple crops–that is, the maximum achievable yield versus the current yield–and how to bridge this gap. They stress that efforts to curb soil degradation are essential to prevent cultivatable land area from deteriorating further, and that improved crop varieties that can adapt to harsher conditions are essential in meeting the future increase in food demand.
The decrease in water stored as groundwater and as soil moisture will have a strong impact on livestock production as well. Already, increasing periods of drought have led to the loss of over one-third of Niger’s livestock in the past year. Such harsh conditions have forced pastoralists to move to different environments, which could expose them to new risks. In the United Kingdom, rising temperatures have increased the abundance and spread of diseases and parasites that affect sheep and cattle, such as endemic helminths.
Meanwhile, animals raised for food continue to contribute significantly to greenhouse gas emissions. One article that investigated the drivers of change in the livestock sector cited a 2006 United Nations report that concludes that livestock are responsible for 18 percent of global emissions. Innovations such as the use of manure and grazing management are recommended, but these may add to the costs of production. To meet growing global demand for meat, eggs, and dairy products, which is expected to surge over the next three decades, experts have proposed “wild card” solutions such as the use of nanotechnology to enable more precise livestock management, as well as “growing artificial meat in vats.” Organizations such as New Harvest are experimenting with “cultured meat” as well as meat substitutes, but such technologies will likely require at least another decade of research to come to fruition.
Fisheries in inland communities may experience challenges from more-intense rainfalls but lower overall flows in rivers and lakes. In the articles that discussed the future of fisheries and aquaculture, experts warn fishery-dependent populations that unfavorable climatic conditions combined with overfishing may lead to the extinction of entire species. At highest risk are fisheries at the “interface of two ecosystems,” such as those in Senegal and Angola, as well as very shallow areas such as estuaries and deltas. Rising sea temperatures are already causing warm-water fisheries to shift toward the poles. Beyond food security, the authors warn about the effects of sea-level rise on low-lying, rural coastal areas that are more prone to flooding. They recommend investing in these communities at an early stage to strengthen their ability to adapt to such crises.
In light of these impending challenges facing conventional agricultural systems, another article explore alternative means of obtaining food, such as foraging and incorporating wild species into regular diets. Upon examining 20 studies in Africa, authors found that typical rural communities already use approximately 100 wild species of plants, and many manage wild species for food uses. These indigenous species could play an important role in diversifying and expanding the food supply and improving food security, while also easing agriculture’s impacts on biodiversity.
Stay tuned for the next post in the series, where we will discuss urbanization, another major challenge and driver of change in the global food system.
To learn more about adapting production methods for limited resource environments and climate change, read Kenyan Professor Promotes Indigenous Food to Solve Climate Change Food Crisis, Nature Emphasizes a Focus on Innovations that Nourish People and the Planet, Traditional Food Crops Provide Community Resilience in Face of Climate Change.
Alex Tung is a research intern with the Nourishing the Planet project.