Kröpelin is a wiry, hands-on man with seemingly inexhaustible energy, whoseems youthful despite his 61 years. In an article titled "Man of the Desert," the journal Nature describes him as "one of the most devoted Sahara explorers of our time." Some see him as part of a tradition established by predecessors like Heinrich Barth and Gustav Nachtigal.
Kröpelin, like these great scholars of the 19th century, is a universalist. He is equally at home with such diverse subjects as stone-age settlements, the ecological importance of solitary wasps and the angles of sickle-shaped migrating dunes.
In Sudan, Kröpelin explored Wadi Howar, a dry valley that was once filled with a large desert tributary of the Nile. He has retraced the trading routes of caravans from the days of the pharaohs, and he has documented climate change on the basis of tentatively sprouting camel grass in the desert.
Most of all, Kröpelin is a gifted storyteller. "I was just in the shower, when " he begins, and before long he is in the middle of a gripping story. Shortly before his departure, he says, he received a call on his satellite phone from a French colleague. The Frenchman and his camel expedition were lost in the canyons of the Erdi-Ma, a barren region in northeastern Chad into which hardly any humans had ever set foot. To help the lost Frenchman, Kröpelin used old GPS notes to direct him to one of the rare watering holes. "He must be out there somewhere," says Kröpelin, pointing to the rocky landscape north of the Ounianga lakes. "I hope he makes it."
"The desert attracts a special sort of person," says Kröpelin, as he seamlessly launches into his next story. This one is about a pedantic botanist, whose Jeep overturned while he was maneuvering his way around the cracked surface of a dry lakebed. But the botanist did not crawl out of the vehicle until he had painstakingly documented the accident in his field book. And then he talks about the time Sudanese soldiers pursued him through the desert for days, until they caught up with him and demanded some of his diesel fuel.
He launches into a discussion of politics. The rumors about Islamist terrorists, the horrific stories from Darfur and now the war in Mali -- all of this, he says, doesn't make working in the region any easier. But the dangers are exaggerated, says Kröpelin, noting that walking through some neighborhoods of New York in the evening is riskier than spending a week in the desert. Nevertheless, fear has driven away some of his fellow geologists. The French, once so numerous, aren't coming anymore, he says. It's also become difficult to find doctoral students in Germany willing to put up with the hardships of working in the Sahara.
But this time the 21st century has found its way into Kröpelin's realm. Before departing from Marseille, the desert explorer excitedly took a picture of the departure board at the airport. He could hardly believe his eyes: The board listed a 3 a.m. departure for a charter flight bound for Faya-Largeau.
Point-Afrique, an adventure travel company, had managed to make use of an old French military airport in the small oasis city in northern Chad for tourism purposes. Now it offers charter flights in the winter season, taking travelers on board a Boeing 737 to one of the most remote spots on the planet. "Unbelievable," says Kröpelin. Making the round trip from his home to his research site within a week is something he has never experienced throughout his entire academic career, he says.
From Faya, it's only a one-day trip in an off-road vehicle to the Ounianga lakes. The journey passes through a wasteland that stretches to the horizon, with one of the giant sickle dunes occasionally blocking the way. Slowly and inexorably, the dunes move across the plain in a southwesterly direction, traveling about one kilometer a century.
Dust-covered tire tracks are the only evidence of a road here, along the main artery between Libya and Chad, as well as the truck tires, scattered at regular intervals, that former Libyan leader Moammar Gadhafi had his troops leave behind during his expedition into Chad. Like Hansel and Gretel in the forest, Gadhafi wanted to mark the route for the trip home.
Until recently, hopelessly overloaded trucks crawled along this path too, bringing goods from Libya to Chad and Sudan. But trade has come to a standstill since Gadhafi was overthrown, and now weeks go by without a single vehicle passing through the region.
Kröpelin's expedition, traveling in three off-road vehicles, also doesn't encounter a single person along the way. A few runaway camels turn up shortly before their destination, where scattered acacia trees indicate that there must be water deep underground there. Then, quite suddenly, the spectacular view of the Ounianga basin appears.
On his first visit to this idyllic green spot in one of the driest places on earth, Kröpelin was so fascinated that he has since fought to place this natural treasure under protection. He achieved his goal last year, when UNESCO declared the lakes a World Heritage site. Kröpelin proudly pulls out a UNESCO map. While there are many sites in Europe, there is only one dot in the vast open spaces of Chad: Ounianga.
But Kröpelin is too restless and enterprising to be satisfied. He has already set his sights on his next goal: to convince UNESCO to add the Ennedi Plateau, more than 200 kilometers farther to the south, to its list. For Kröpelin, the plateau's uniqueness is beyond question. "Monument Valley is nothing by comparison," he says. The region is also culturally significant, he adds. "You won't find stone-age cliff drawings like the ones in the Ennedi anywhere else in the world."
Dreams of a Green Sahara
Kröpelin is fascinated by the relationships among the histories of the climate, the earth and mankind. He is interested in how people responded to change in the Sahara. Here in the inhospitable dryness of the desert, blades and arrowheads made of quartzite or ring-shaped traces of settlements are evidence that Homo sapiens were once omnipresent in the Sahara.
"A Stone-Age burial mound," Kröpelin says, pointing to one of the piles of stones rising from the plain. "What's so fascinating about it is that everything is preserved in just the way it was left thousands of years ago."
During an expedition into the no-man's land east of the Ounianga lakes, Kröpelin even believes he found traces of an ancient Egyptian caravan. He discovered a stone statue of a man, visible from far away on a high plateau, similar to the statues uses on mountains today as guideposts for hikers. Kröpelin suspects that what he had found was a landmark for desert travelers from the days of the pharaohs.
There is evidence that the expeditions from ancient Egypt extended to at least the current Egyptian-Libyan border, says the geologist. A few years ago, hieroglyphics were found there, at Uwaynat Mountain. Kröpelin thinks it is conceivable that traders stopped there to replenish their water supplies before continuing their travels toward Ounianga.
To reinforce his theory, he points to the eroded cliffs that shape the landscape along the shores of the Ounianga lakes. Over the millennia, the constant wind has carved them into step pyramids.
Kröpelin believes that the similarity between this shape and that of structures along the Nile is more than coincidental. He theorizes that gradual desertification drove the Egyptian people out of their original habitat, which is now the Sahara Desert. He points out that silhouettes of the tombs of the pharaohs, visible from a great distance, are characteristic of precisely the region that was once home to the Egyptians.
Will a return ever be possible? Will the Sahara turn green again one day?
Even Kröpelin knows that by answering these questions he is delving into the realm of speculation. Nevertheless, he is gathering evidence.
A rare rainfall over the otherwise dry Sudan in 1988 awakened his suspicions for the first time. If everyone was talking about climate change, why shouldn't the monsoon in Africa be changing, too? Perhaps global warming could drive it back to the state it was in once before, after the ice age.
Since that rainstorm in Sudan, Kröpelin has been recording all signs of climate change during his trips, looking for answers to questions like: Where is camel grass growing more abundantly than in previous years? How productive are the few watering holes? And what are the camel herders and date farmers saying?
Of course, all of this is merely anecdotal evidence that doesn't stand up to scientific scrutiny. Nevertheless, Kröpelin is convinced that the evidence is growing. In fact, he says, he even believes that there is now real evidence of change, and that the desert is getting greener.
The geologist feels validated by recent news from the Faya oasis. Last summer, residents told him, they were surprised by a sudden downpour. Huts were washed away and people drowned. This had never happened before, they said.