High temperatures and changes in rainfall patterns are likely to reduce cereal crop productivity due to climate change in African countries, and new evidence is emerging that high-value perennial crops will also be negatively impacted by rising temperatures. Pressures from pests, weeds, and diseases are also expected to increase, with detrimental effects on crops and livestock.
Climate change and agriculture are interrelated processes, both of which take place on a global scale. Climate change affects agriculture in a number of ways, including through changes in average temperatures, rainfall, and climate extremes (e.g., heat waves); changes in pests and diseases; changes in atmospheric carbon dioxide and ground-level ozone concentrations; changes in the nutritional quality of some foods; and changes in sea level
Indeed,Series of report indicate that ,Climate change is already affecting agriculture, with effects unevenly distributed across the world.Future climate change will likely negatively affect crop production in low latitude countries, while effects in northern latitudes may be positive or negative. Climate change will probably increase the risk of food insecurity for some vulnerable groups, such as the poor
Agriculture contributes to climate change by (1) anthropogenic emissions of greenhouse gases (GHGs), and (2) by the conversion of non-agricultural land (e.g., forests) into agricultural land. Agriculture, forestry and land-use change contributed around 20 to 25% to global annual emissions
Despite technological advances, such as improved varieties, genetically modified organisms, and irrigation systems, weather is still a key factor in agricultural productivity, as well as soil properties and natural communities. The effect of climate on agriculture is related to variabilities in local climates rather than in global climate patterns.
The Earth’s average surface temperature has increased by 1.5 °F (0.83 °C) since 1880. Consequently, agronomists consider any assessment has to be individually consider each local area
The climatic change could affect agriculture in several ways :
1-productivity, in terms of quantity and quality of crops
2-agricultural practices, through changes of water use (irrigation) and agricultural inputs such as herbicides, insecticides and fertilizers
3-environmental effects, in particular in relation of frequency and intensity of soil drainage (leading to nitrogen leaching), soil erosion, reduction of crop diversity
4-rural space, through the loss and gain of cultivated lands, land speculation, land renunciation, and hydraulic amenities.
5-adaptation, organisms may become more or less competitive, as well as humans may develop urgency to develop more competitive organisms, such as flood resistant or salt resistant varieties of rice
Here are some of the changes to be expected if global temperatures rise,
1– Rainfall patterns would shift: Around the 2080s, annual precipitation may decrease by up to 30% in southern Africa, while East Africa will see more rainfall.
2– Heat extremes would occur more often: By the 2030s, when temperatures could be 1.5°C warmer, previously unprecedented heat extremes would cover one-fifth of the land areas in the southern hemisphere during the summer.
3– Dry, arid regions would spread: Arid regions would expand by 10%, particularly in Southern Africa and parts of West Africa.
4– Sea-level would rise: The sea-level is expected to rise by 50 cm by 2060, threatening important seaports
But then What does this mean for African agriculture and food security in the entire African region?
1-Farmers would see lower crop yields: Maize, wheat and sorghum are all sensitive to high temperatures. As heat extremes exceed these thresholds more often, these crop yields would diminish.
2– Farmers would also lose arable land: As global average temperatures increase 1.5°C to 2°C by 2040, drought and aridity would contribute to African farmers’ losing 40 to 80% of their croplands used to grow maize, millet and sorghum.
3– Less food would be available to eat: Warming patterns mean that per capita cereal production would be 10% lower in 2050 than in 2000. If we also consider the effect of food trade, potential food availability per person actually drops by 15%.
4– Malnutrition would also increase: Without climate change and other policy interventions, the number of malnourished children in Africa will likely increase from 33 million to 42 million. Climate change could mean a further 10 million children suffer from malnutrition.
Africa is one of the continents that is most highly affected by climate change for two reasons: its geographical characteristics of having a majority of land lying across the warming tropics, and the limited human, social and economic capacity that African countries have to adapt to the impacts of climate change