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Thanks to Climate Change, the Sahara is Inching South

The desert, which is roughly the size of the United States, has grown by about 10% in the last century, in large part thanks to climate change.

BySamia BouzidNOVA NextNOVA Next
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Climate change has helped dry out African summers, feeding the growing Sahara.

While the face of climate change often looks like dramatic natural disasters—hurricanes, massive fires, floods, or heat waves—the African continent is facing a much more subtle catastrophe: the spread of the Sahara.

The desert, which is roughly the size of the United States, has grown by about 10% in the last century, in large part thanks to climate change. Researchers worry that this slowly unraveling disaster hasn’t gotten the attention it warrants to prepare affected populations for the consequences.

Here’s Darryl Fears, writing for The Washington Post:

“If you have a hurricane come suddenly, it gets all the attention from the government and communities galvanize,” said Sumant Nigam, a professor of atmospheric and oceanic science at the University of Maryland and the senior author of the study. “The desert advance over a long period might capture many countries unawares. It’s not announced like a hurricane. It’s sort of creeping up on you.”

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In fact, the governments of Sudan and Chad have barely noticed, despite the fact that their rainy season has traded itself in for a dry spell that has allowed the desert to creep south.

But what might not be clear in the day-to-day stood out in the data. Researchers studied 93 years of climate data beginning in 1920 and found that climate change is likely helping drive the southward spread, for two reasons.

First, shifting weather patterns driven by climate change are likely widening what’s called a “Hadley cell,” a region of dry air that leads to the formation of deserts. That’s compounded by drier-than-usual stretches in the Sahara’s natural 50- to 70-year cycle of wetter and drier periods.

Most alarming to the researchers was the discovery that the spreading is happening during the African summer, which is typically rainy in the regions just south of the Sahara. Loss of the rainy season threatens agriculture, which currently supports 80% of Sudan and Chad’s workforce. And although the African continent is least responsible for global climate change, its populations continue to suffer the brunt of its consequences on account of its geography.

Yet, while this research focused on the Sahara, deserts around the world are also likely inching wider. The study’s senior researcher suggests that it’ll take long-term planning to protect water resources as disasters like these play out.

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