Climate tipping points are much more fantasy than science Sahara has been shrinking over the past decades. Image: NASA Dr. Kröpelin is an award-wining geologist and climate researcher at the University of Cologne and specializes in studying the eastern Sahara desert and its climatic history. He’s been active out in the field there for more than 40 years. In the Auf 1 interview, Dr. Kröpelin contradicts the alarmist claims of growing deserts and rapidly approaching climate tipping points. He says that already in the late 1980s rains had begun spreading into northern Sudan and have since indeed developed into a...