As average global temperature begins to rise due to human activity, scientists say the drastic effects of climate change continue to take effect all over the world. One of the intensely affected sectors is the field of Agriculture.
Africa is expected to pay a significant cost of the damage caused by climate change. Pervasive destruction of farms in recent flooding in some parts of Africa and the prolonged drought in Ethiopia, further demonstrates the extent of the threat posed by Africa’s changing climate.
According to an expert on global food security and sustainability, Professor Navin Ramakutty of the University of British Columbia “the food system is already stressed in many ways”.
Ramankutty in his new study featured in the journal Nature, examined the link between weather related disasters and food production. He along with a team of researchers from UBC and McGill University discovered that extreme heat waves and droughts have reduced global cereal harvests such as maize, wheat and rice by 10 per cent in a span of 50 years.
Although concerns about climate change are global and real, its consequences on African Agriculture are quite enormous. In his paper titled “Impact of climate change on agriculture in Africa by 2030” Joseph Khaoma, a researcher at the School of Environment and Earth Sciences, Maseno University Kenya notes that warmer climate will disrupt and interfere with the natural ecosystem stability and adaptation such that grassland and desert ecosystems will expand in area while the rich forest ecosystems will reduce in area.
Marginal agriculture as practiced in the Arid and Semi-arid lands (ASAL) regions will probably suffer most because the ASAL will be hotter and the natural ecosystems may not easily adapt to new harsh conditions. These may lead to extinction of ASAL ecosystems mainly the drought resistant crops.
Joseph further observes that the current ecological hazards of droughts desertification and soil erosion may worsen making the areas where they occur unsuitable for living in future.
Global warming would also have major adverse effects on water use and availability in the tropics making large reservoirs and other irrigation projects dry up and become useless long before their normal 50 years lifetime has elapsed. Africa has some of the major irrigation projects such as the Gezira for cotton.
A warmer climate will adversely affect food security in Africa, for example, 96 per cent of Egypt is desert and 97 per cent of the population is concentrated only on four per cent of the Irrigated land (Jackson, 1989). If the Nile Waters used for Irrigation dries up, then there will be no food and the people of Egypt will migrate to other habitable regions in the temperate lands.
Climate change could also reduce the human population. People currently living along the coast, in arid and semi arid lands will be forced to migrate to the climatically habitable continents. The Arabs in North Africa may move to Europe. There will be a halt on industrialization since cash crop cultivation, which is the basis of industrialization in Africa, will be drastically reduced. Giant irrigation projects such as the Gezira in Sudan may disappear due to drying up of the Nile River.
Are there benefits of global warming?
In a report published on October 12 2016, a former delegate of the Intergovernmental Panel on Climate Change (IPCC), Dr Indur Goklany says global warming is not totally catastrophic as projected and that carbon emissions for instance are actually good for agriculture. In the paper, Gloklany called for a reexamination of carbon dioxide, which according to him has numerous positive effects on nature and humanity.
One of the points raised by Goklany is the ability of carbon to fertilize plants, which has already resulted in increased fossil fuel emissions – a great contributor to the health of crops. Carbon fertilization according to Techtimes.com is said to be accountable for increasing yields by 10-15 at the minimum.
He further says “estimated worth of global fertilization impacts coming in from carbon dioxide is $140 billion a year, and this extra production has provided assistance to hunger reduction and human health improvement”.
Glokany notes that the nature may benefit from lands not utilized by crops. According to him “the wild places on the planet have become greener in the past decades due to increased carbon dioxide. Another thing is carbon dioxide has been found to boost the water use quality of plants, compelling them to become stronger in the face of drought – double benefits in dry regions”.
Coping with the tide
Crop breeding for development of new climate tolerant crop varieties is a key tool for adapting agriculture to a changing climate. History and current breeding experience indicate that natural biodiversity within crops has allowed for plant adaptation to different conditions, providing clear evidence that plant breeding has great potential for aide in the adaptation of crops to climate change.
Cropping system is another tool that can help agriculture adapt. For example the use of crop mixtures that have several crops growing at o ne time can help systems exhibit greater durability during periods of high water or heat stress.
According to the American Association of Advance Science (AAAS), researchers would have to develop drought resistant crops that have been tested for strong yields when subjected to periods of extended water shortage. Improvements in plant nitrogen and water use efficiency and development of cost efficient nitrogen uptake delivery systems and low cost irrigation technique.
There should also be development of global testing sites and data collection and dissemination efforts using standard data protocols to assess the performance of existing and new genetic material and management system in today’s range of agro climatic conditions.
Continuous field testing to track climate change, breeding for resistance to new diseases and pests and to address changes in pollinator distribution should also serve as avenues to confront adaptation of crops in the face of climate change.