The Sahara is shrinking (not expanding)

Dr. Stefan Kröpelin is an award-wining geologist and climate researcher at the University of Cologne. He specializes in the eastern Sahara desert, specifically its climatic history, and has been active out in the field for more than 40 years.

Contrary to other evidence that the Sahara suddenly changed from a wet to dry climate 5,000 years ago, Kröpelin's core samples at Lake Yoa in northern Chad suggests the transition took longer, some 3,000 years from 5,600 to 2,700 BC[1].

In an interview, given on November 9, 2023, Dr. Kröpelin confronts the alarmist claim of expanding desertification and looming climate ‘tipping points’.

He states that even back in late-1980s rains had begun spreading into northern Sudan, with the rains increasing ever since leading to a vegetation spread northwards and the emergence of a trend: “The desert is shrinking; it is not growing.”

When the last glacial period ended some 12,000 years ago, explains Kröpelin, the eastern Sahara turned green with vegetation, it teemed with wildlife, and also had numerous bodies of water even as recently as 5,000 years ago.

"The most important studies that we conducted all show that after the ice age, when global temperatures rose, the Sahara greened … the monsoon rains increased, the ground water levels rose."

This all led to vegetation and wildlife thriving, but then over the past few thousands of years, the region dried out. It didn’t happen all of a sudden like climate models suggest, Kröpelin stresses.

When asked about dramatic tipping points, such as those claimed by the Potsdam Institute (PIK), Kröpelin says he is very skeptical when it come to 'crisis scenarios' 'such as those proposed by former PIK head, Hans-Joachim Schellnhuber, saying people making such claims "never did any studies themselves in any climate zone on the earth and they don’t understand how complex climate change is."

Barring catastrophic geological events, "it’s not how nature works," says Kröpelin. "Things change gradually."

The claims that "we have to be careful that things don’t get half a degree warmer, otherwise everything will collapse, is of course complete nonsense … I would say this concept [tipping points] is baseless."

Anyone who approaches the climate with control technology terms (feedbacks, negative feedbacks, trigger points, tipping points) has not understood something essential: Nature does not work with controlled variables, control algorithms or manipulated variables because it neither measures anything, sets anything nor uses algorithms. Everything that takes place in nature and in the entire universe are balancing processes.

[1] Francus et al: Varved sediments of Lake Yoa (Ounianga Kebir, Chad) reveal progressive drying of the Sahara during the last 6100 years in Sedimentology - 2013