Wednesday 5 May 2010

Climate Change Projections for Africa

So the 26th Region Conference for Africa is in session this week and one of the items on the agenda is improving food security in the face of recent climate trends. A report on the impact of climate change in Africa has been prepared which summarises the plight of the continent and discusses a number of options for fighting back. In this post I’ll deal purely with the climate change projections.

Africa has a long history of food crises but one of the main reasons why it is particularly vulnerable to climate change is that it is particularly reliant on rain-fed agriculture. Irrigation and water conservation are poor throughout Africa and changes to rainfall patterns due to Global Warming could have a significant impact on annual soil moisture levels.

The most vulnerable regions are the semi-arid countries around Sub-Saharan – where population growth is higher than any other region in the world – and also South Africa and some of its neighbouring countries. These regions are predicted to show reduced rainfall all year round, threatening a potential water crisis.

This has to some extent already begun. Over the last 40 years many of Africa’s major water courses have seen a 40-60% reduction in discharge. Lake Chad has been reduced from 20,000km2 in the early 1960s to less than 2,000km in the early 21st century. While this statistic may not be as bad as it appears – Lake Chad is a historically shallow lake – it still demonstrates that Africa is already on the path to disaster.

Further reductions in river discharge, due to decreases in rainfall, are likely to affect agriculture that depends on these rivers for irrigation. Agriculture along the Nile is particularly vulnerable.

Coastal and tropical regions, among others, are likely to experience slight increases in rainfall, but this is not necessarily a good thing for farmers either. The increase is likely to be seen during the winter months, with an extra 5 – 20% between December and February and a reduction of 5-10% between June and August. There is also likely to be greater variability between wet years and dry years. Combined, these trends mean that, while overall rainfall might increase, the number of droughts will also increase.

Finally, some coastal regions in countries such as Mozambique, Tanzania and Angola are at risk from rising seas, while coral reefs could also be destroyed by higher sea temperatures.

So the overall picture for Africa? Pretty bleak – especially considering that its population continues to rise and much of its existing farmland is slowly being degraded. I’ve already mentioned some of the implications for agriculture here, but the next post will focus on purely food production.

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