Large areas of Africa receive little rainfall for much of the year, so even though Africa covers 20% of the world's land area, it only has 9% of global freshwater resources.

UNESCO: Education

During the first half of the twentieth century, as global temperatures rose in the aftermath of the Little Ice Age, rainfall in the Sahel increased dramatically.

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Parts of the country recorded high rainfall and little sunshine.

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The researchers also say there was little change in the amount of rainfall in the region over the last few decades and so could not account for changes in glacier retreat.

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And there's been an increase in rainfall at higher latitudes as a consequence because the atmosphere can hold more water if it's a little bit warmer.

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