‘The cause of the warming of the African continent (and of the world as a whole) over the past 100 years is not clear.
The change in atmospheric composition associated with rising levels of greenhouse gases must be one of the most plausible explanations, but there are other possibilities (Wigley et al. , 1992). The trend may, for example, be the result of natural climate variability, shifts in the ocean temperature distribution or changes in the solar output.The progressive degradation of dryland areas, by reducing surface soil moisture, may have contributed to the warming over Africa, although the results of recent analyses suggest that the effects may account for no more than a small proportion of the trend observed over the continent as a whole (cf. Balling, 1991, with Hulme and Kelly, 1993). Whatever the cause of the warming trend, it provides one benchmark against which we can judge the projections of future climate warming for Africa’All that one needs to look at is the Annual rainfall during the mosts recent three decades to see that there has been around 20 to 40 percent less than was expected around the 1960’s.
Take extreme years such as 1984 and 1990 where rainfall levels have dropped below 50 percent of what is normally expected. But the real question we are trying to answer here is how sensitive are African natural resources, managed ecosystems and national economies to the level of climate change which Africa is likely to encounter.So, we need to understand what will the increase in temperature in the southern hemisphere do to Africa in particular. If we look at the research put forward by some American’s -(source not stated) then across the whole continent of Africa, on average violence and conflict was around 50 percent more likely to occur in abnormally warm years.
The cause of this according to PNAS – National Academy of Sciences, is that people become uneasy and increasingly worried about the food supply when they see that the crops have had a particularly bad year generally this happens in times of extreme heat.An example of this is fighting in Darfur which took place killing 200,000 people and pressured two million people into evacuating from their homes and lives to escape it. Another example is the extended study between the years of 1981 to 2002 where researchers looked for trends to show correlation between above average heat and civil conflict which may result from it. The results came up positive showing that conflict was increased by 50 percent as a result of the deaths of 1000 people.
But why is the increased temperature having such ill side effects.Perhaps one explanation is that crop yields are very sensitive throughout Africa because the land holds little nutritious value and even less water. So because of this an increase in temperature beyond what is expected can mean the land becomes very barren even at a 0. 5 degree celsius increase creating mast crop extermination. These crops are one of the very few lifelines for many Africans, so as a result conflict takes place. Even cereal crop yields could fall between 10 to 30 percent by the 2050s compared to 1990 levels and that is considered a robust crop.
Agriculture in Niger is also particularly sensitive to fluctuations in rainfall because the rainy season is already short (i. e. , agriculture is marginal). In a similar historical study, found for Kenya that the driest 10% of years coincided with reductions in maize yield of roughly 30% to 70% and of forage yields of 15% to 60%. Africa’s current contribution to global markets (both for export and for consumption) is relatively small and highly variable depending on weather conditions and pricing policies.
The region possesses a marked intra- seasonal and inter-annual variability of rainfall making it a high-risk environment for agriculture. To meet future food demands of the growing population, regional crop production by 2035 will have to expand by an estimated 3% per annum. In South Africa, 89% of the land area is currently used for agriculture with about 35,000 ha of land lost annually to urban and industrial expansion and afforestation.
The effects of growing demand and shrinking area of agricultural land are forcing agriculture into more marginal areas with ever greater sensitivity to climate variability.