Agriculture is affected by climate change. A joint study by the Consultative Group on International Agriculture Research (CGIR) and the Dutch-based Technical Centre for Agriculture and Rural Cooperation (CTA) created by the EU and the African, Caribbean and Pacific countries (ACP), presented last September gave further evidence of it. Higher temperatures, rainfall changes and more acute droughts and floods are indeed caused by the increase of greenhouse gas (GHG) emissions, says the report.
But agricultural activities are also factors of climate change. They generate indeed 10% of GHGs and 5,100 to 6,100 mega tonnes per year of carbon dioxide (CO2) or the equivalent of all emissions from the transport sector. Moreover, agricultural activities are responsible for other gas emissions with a strong impact on the climate. Most of the CO2 produced in this context comes from the clearing of forests for farming.
As a result of these trends, climate change is posing a serious challenge to food security. Whereas one billion people are already suffering from hunger, food production will have to increase by 70% to cover the needs of the world population which will grow to 9 billion by 2050, says the study.
According to the 2007 forecasts of the Intergovernmental Panel on Climate Change (IPCC), a 2°C increase between now and the end of the 21st century will lead to considerable changes in the use of land. But effects will differ according to regions. Indeed, the United Nations Environment Programme (UNEP) is projecting higher cereal yields in the boreal areas of the Northern hemisphere by 2080. If the current trends continue, a decrease of yields up to 50% will occur in Southern Africa, Maghreb and Sahel while a 10 to 15% decrease will happen in Western Africa.
Island countries will be the worst hit, especially the Caribbean. Longer dry seasons are expected there. And owing to higher sea levels, more intrusions of salted water are expected in the rivers and lagoons while a rise of the water temperature and of the sea water salinity should trigger lower fish production.
But the worst case scenario can be avoided, says the CTA which proposes a set of “smart agriculture” solutions that would increase food production while reducing GHG emissions. In Sub-Saharan Africa for instance, water storage will be increasingly crucial to allow the use of water stored during rainfalls in the dry season. Livestock farmers will need to improve the management of pastures and the food regime of the cattle, while farmers will have to prioritize crop varieties which are more resistant to hydro stress. A whole range of irrigation techniques (such as drip-drop) do exist but they require transfers of know-how to the farmers. Positive experiences have taken place in Burkina Faso where the German NGO Welthungerhilfe’s water and soil conservation programmes have benefitted to 1.3 million people.
« Conservation agriculture » provides a solution as it improves the capacity of the soil to store water and nutrients. For instance in Zambia 180,000 farmers are implementing a technique consisting in the provision of perennial soil cover with organic material to protect it against high temperatures. As a result, these Zambian farmers have managed to obtain maize yields three times higher than the national average. Between today and 2015, China is planning to develop a programme of soil protection on 2.7 million hectares to improve soil resilience to droughts. In Ethiopia, an EU-UN sponsored food safety-net programme is benefitting 8 million people and has allowed to rehabilitate millions of hectares of arable land. Agro-forestry is another response. In Niger, the government has encouraged the cultivation of Faidherbia albida, a tree whose azote-rich leaves fall during the rains and improve soil fertility. As a result, sorghum yields have significantly improved. UNEP satellite pictures show that the Tahoua province has grown green again owing to reforestation between 1975 and 2000 in Niger.
The response to climate change includes the mitigation of its effects. In Kenya, the International Livestock Research Institute created an insurance scheme that benefits 2,500 farmers which is triggered when fodder becomes scarce. The Agriculture Insurance Company of India is offering compensations ranging between 60 and 90% of the value of an average crop to its 29 million affiliates to protect them against the effects of bad crops.
In her documentary broadcasted last October by the French-German “Arte” TV-Channel, titled« The crops of the future », French journalist Marie-Monique Robin, shows the merits of agro-ecology. It is based on the principle of biodiversity and on organic material soil cover, as opposed to industrial agriculture using pesticides. One example is the milpa ancestral system of Mexico. It combines the cultivation of several crops on the same plot of land, which allows pumpkins to grow under the shadow of maize while beans grow around the maize stems. This technique provides better soil protection, less parasite problems and above all no dependence on genetically modified organisms and chemical pesticides. The « push-pull » technique developed by the Berkeley University which is based on the attraction and repulsion phenomenon between plants and parasites is being used increasingly.