Impact of Climate Change on African Agriculture: Focus on Pests and Diseases

The latest CGIAR report on the impact of climate change on African agriculture argues that increased regional temperatures and a greater risk of pests and diseases will affect crop, livestock, and fisheries productivity throughout Africa. Without effective adaptation measures, regional production of maize and beans could decrease by up to 40% relative to the period 1970-2000, leaving areas like Eastern and Southern Africa with a need to rapidly adapt in order to improve and ensure food security.

Crops like sorghum, cassava, yam, and pearl millet have generally experienced small losses, and even gains in some places, in production area; these crops could thus become a viable alternative for Eastern and Southern African farmers. Western Africa could find itself in a vulnerable position since climate changes could reduce suitable planting areas for maize, sorghum, and other crops by more than 10%.

Climate change, population growth, and an increase in world trade may all contribute to a higher prevalence of crop pests and a more frequent occurrence of major pest outbreaks. According to the report, crop pests account for around one-sixth of farm productivity losses. A higher incidence of pests would require more pesticides, which would in turn increase the risk of hazardous residues in food.

Higher temperatures will negatively impact livestock productivity through two channels; i) a reduction of feed intake, since most domesticated species perform best at temperatures between 10 and 30 °C and will eat around 3-5% less for each 1°C increase above those levels and ii) higher temperatures, which will mean substantial reductions in forage availability.

Rising temperatures and humidity will also increase the rate of development of parasites and diseases that affect livestock, such as trypanosomosis, East Coast fever, and Rift Valley fever; disease outbreaks that may reduce exports and cause farmers lose profits are projected to worsen as temperatures rise. Livestock diseases also have impacts on human health. According to the report, over 60% of pathogens that cause human disease come from animals.

Fishery production in Africa could also be greatly affected. The report identifies fisheries in 23 African countries as highly vulnerable to climate change. These impacts will have negative effects on the incomes and food security of millions of African producers.

The report’s authors argue that strategies do exist to address the impact of pests and diseases on agricultural systems. Such strategies will require: i) capacity enhancement of regional, national, and local organizations; ii) increased coordination at the regional and continental levels; iii) improved data quality and quantity to allow for science-based response strategies; iv) pre-emptive breeding of pest- and disease-resistant varieties; v) increased resilience of agricultural production systems; and vi) further research and development to predict and respond to pest outbreaks.  Using a variety of strategies ranging from individual measures like shifts in planting dates or crop substitution to systemic changes like livelihood diversification, targeted trade policies, and shifts in populations’ diets, adaptation to climate change is possible.