Q Climate change
in South Africa
with currently unknown organisms, that are likely to threaten crop yields and human health. So you can see that climate change not only has an impact on agriculture, but that it is likely to have a considerable impact on farmers because of their dependence on the climate. The occurrence, timing, frequency and intensity of climatic events, for example rainfall, as well as the distribution of these events within a season of growth, have definite impacts on agricultural production. And these effects will be felt in both the formal and informal agricultural sectors. Water – the main ingredient Much can and should be done to reduce CO2 levels nationally, for example by encouraging the development of renewable energy sources and the industry that can arise around these. However, it is the farmer, his family and the rest of us who will fell the impact of climate change at the local level. Farmers can do plenty to try to reduce their own CO2 emissions, such as moving to a no-tilling system of crop management. However, farmers are going to have to find innovative ways to adapt to a changing climate. In the past it was possible for commercial farmers to rely on ample surface
Top: Rainwater harvesting in practice near Thaba Nchu. Image: James Blignaught
Above: Water restoration in progress on an ostrich farm near Oudtshoorn. Image: Sue Milton
and ground water resources and, through irrigation, buffer themselves against the effect of changing climatic conditions. With climate change, water availability will be under increasing pressure and water will eventually become a luxury as the demand for water, especially in urban areas and by the manufacturing sector is rising and the supply becoming more erratic.
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gas layer around the outer edges of the atmosphere that allows the rays of the sun to enter the atmosphere, but which prevents the reflected heat to escape. This is refered to as the ‘greenhouse effect’ and leads to a build up of heat within the atmosphere. This build up of heat causes changes in climatic patterns and processes, such as the melting of icebergs, glaciers (e.g. on the top of Mount Kilimanjaro), and increased rates of evaporation and transpiration of water, which has serious consequences for farming. Climate change in Africa While Africa is the continent with the lowest CO2-emission levels and rates, it is arguably one of the most vulnerable to changes in climate. There are various reasons for this: ■ Africa’s generally low levels of income ■ Africa’s, by and large, hot and relatively arid climate ■ Agriculture is one of Africa’s main forms of livelihood and income ■ The increase in the frequency and intensity of extreme climatic events, which will almost certainly reduce, on average, crop and animal production. These changes are likely to vary from year to year and from region to region. These changes are also likely to have a major impact on the production, access and distribution of food ■ Varying climatic conditions will probably also change the rainfall regimes and have an impact on water security ■ Africa does not have the resources to import large amounts of food, and/or to invest in climate adaptation programmes ■ Africa still has to develop its energy sector (implying, most probably, more CO2 emissions) to allow economic development, and ■ Africa has neither the expertise nor the financial and other resources to map and monitor the distribution and spread, and to combat invasive alien organisms (e.g. exotic plants) but also pests and diseases that are likely to become more widespread on a warmer climate, such as cholera and malaria. Climate change may also lead to worse pest infestations, possibly
No-tilling is the word used for a system of farming in which crops are planted without ploughing or using herbicides to control weeds, which results in less soil erosion and lower losses of soil nutrients.
Quest 5(4) 2009 29