Wheat, which is grown on 220 million hectares, is cultivated on more land than any other crop. Wheat can tolerate a wide range of temperatures and precipitation levels and grows on a number of types of soils. The most common wheat species are bread wheat (Triticum aestivum) and durum wheat (Triticum turgidum). Both species play an important role in feeding the World.

By 2050, demand for wheat is predicted to increase by 50 percent from current levels. Declining wheat productivity and rising wheat prices will have the most profound impact on countries that have high rates of poverty and depend on wheat for food security. As climate change potentially drives production into higher latitudes, the livelihoods of small-scale farmers, particularly in the global South, will become increasingly at risk.

China, India, the Russian Federation, North America and Northwest Europe are ranked as the top wheat-producing countries and regions. Globally, wheat is second only to rice as a source of calories and is the most important source of protein. Wheat supplies up to half of all calories in North Africa and West and Central Asia.

Climate change, which is being driven by increasing concentrations of carbon dioxide and other greenhouse gases in the atmosphere, is having a number of observable impacts, such as drought and higher temperatures, and these impacts are predicted to reduce crop yields and affect global food production. Generally, reduced yields result from a combination of factors, including adverse extreme temperatures, disease threats (e.g. wheat rusts), decreased soil fertility, and declining efficiency in the use of inputs in conventional cropping systems. This combination of factors is increasing the demand for new crop varieties.

The International Center for Agriculture Research in the Dry Areas (ICARDA) and the International Maize and Wheat Improvement Center (CIMMYT) predict that by 2050 higher temperatures will reduce wheat yields in developing countries by approximately 20 to 30 percent. The McKinsey Global Institute has projected that by 2030, wheat farmers will be 11 percent more likely to see a 10 percent or greater yield decline in any given year compared with the present, and the same decrease is predicted to be 23 percent more likely by 2050.

INCREASED ATMOSPHERIC CONCENTRATION OF CARBON DIOXIDE

There is little clarity regarding the impacts of elevated levels of carbon dioxide on the yield and the nutritional attributes of wheat. However, some experiments under controlled environments and modeling exercises, suggest that the increased concentration of carbon dioxide in the atmosphere could increase photosynthesis rates and productivity in C3 plants (i.e. plants that produce a three-carbon compound during photosynthesis) such as wheat. This increase could partly negate the impacts of climate change on wheat production. However, the increased concentration of carbon dioxide in the atmosphere may reduce the nutritional quality of wheat. For example, when wheat is cultivated under elevated concentrations of carbon dioxide in the atmosphere, the grains may have less protein, zinc and iron. Crop response to elevated carbon dioxide will most likely depend on environmental and crop management factors. More research in this area is needed.

IMPACTS OF WHEAT PRODUCTION ON CLIMATE CHANGE

In addition to being affected by climate change, wheat production also contributes to greenhouse gas (GHG) emissions. In wheat production systems, the primary sources of GHG emissions are associated with conventional crop production practices. These practices include conventional tillage, which leads to a loss of soil organic carbon; the use of nitrogen fertilizers and pesticides, which contribute to emissions of non-carbon dioxide GHGs (e.g. nitrous oxide); and emissions from agricultural operations (e.g. electricity consumption for irrigation and fuel consumption in agricultural machinery).

Wheat production systems need to adapt to ensure they continue to contribute to food security, rural livelihoods and sustainable food systems under a changing climate. The specific adaptation and mitigation approaches will vary according to location. In the world’s wheat-producing regions, there are a wide variety of agro-ecological conditions, microclimates within the soil, climate risks and socio-economic contexts. It is crucial to collect data and information to determine the best course of action and adapt practices to local needs. This information allows for a continuous learning process and can feed into the improvement of future policies. Close coordination and collaboration among stakeholders at all levels are needed to build an enabling environment that gives farmers opportunities to adopt targeted measures to enhance the productivity, resilience and sustainability of wheat production in the face of climate change.

The precise challenges that will be created by climate change on wheat production systems remain uncertain. These challenges will vary from one farming communities to another, but it is certain that they will be especially daunting for countries already coping with high levels of food insecurity. However, there is a clear way forward to meeting these challenges. Options include the adoption of context-specific good agronomic practices, such as conservation agriculture; efficient water and nutrient management; and IPM. These options will complement the gains that can be made through the cultivation of improved varieties.

REFERENCE:

FAO. 2022. Crops and climate change impact briefs. Climate-smart agriculture for more sustainable, resilient, and equitable food systems. Rome. https://doi.org/10.4060/cb8030en