Climate Change Clues From The Ice Age
Studying artifacts from 10,000 to 20,000 years ago, scientists now understand more than before about how climate change affected human behavior.
MUNICH — "We are the first generation to feel the results of climate change," President Barack Obama said recently. He's correct insofar as man-made climate change is concerned, but the statement is a joke if applied to human history.
Humans experienced at least one rapid warming of the planet at the end of the Ice Age 10,000 to 20,000 years ago. The landscape in Europe then was completely different than what it is now, with large herds of reindeer, horses and bison roaming through Germany and large parts of Western Europe. Magdaleniansteppe hunters followed the roaming animals. Accustomed to hard, cold winters, the hunters lived in large communities and followed strict rules. They used every bit of the animals they hunted, even crushing reindeer bones and boiling them to yield bone fat. Discipline ensured survival.
"Society was strongly interconnected, and there were basic rules of behavior," says Sonja Grimm, an archeologist at the Research Institute of Archeology at the Romano-Germanic Central Museum in Neuwied. "Everything was designed for safety in raw, cold surroundings. It would have been fatal if, for example, humans missed the reindeer migrations."
When the glaciers began to melt, people had to come to terms relatively suddenly with dramatic environmental change. Climate change then lasted for some 10,000 years, but it didn't get warmer all at once. The average temperature rose twice within a few decades by more than 10 °C (50 °F), as scientists measuring ancient ice cores in Greenland have shown. It was a markedly more extreme jump than that caused by man-made climate change in the 20th and 21st centuries.
"It was a time of much movement climatically," says archeologist Stephan Heidenreich of the Baden-Württemberg State Office for the Preservation of Monuments. In between, temperatures also fell by several degrees, and then ice once again covered large parts of Europe.
"The settling of Europe took place in this time frame," Heidenreich says. The days of the Magdalenian hunters were over. The signs of their culture, such as spear tips or harpoons made of reindeer antlers, disappeared. Now hunters honed spear tips from stone. Archeologists call the people of this subsequent culture "Federmesser (feather knife) groups" based on the typical form of the weapons. To find out what role climate change played in the cultural transition, archeologist Sonja Grimm compared finds from 25 sites with chemical evidence such as pollen deposits, which contain important information about the environment. Grimm analyzed a time frame of 3,000 years starting in 14,000 BC.
How warmer temps change behavior
Milder winters meant a loosening of the strict behavioral rules observed by Magdalenian culture. "Finds show that people no longer crushed and boiled the bones of dead animals," Grimm says. "They used less of their prey."
Grimm was particularly struck by the change in art. Ice Age hunters created sculptures and engravings: Their cave paintings and slate slabs show true-to-life renditions of people and animals. The Federmesse groups, on the other hand, produced abstract art. Instead of showing rounded women like their predecessors, for example, "They limited themselves to a line for the upper body and a triangle for the backside," Grimm says.
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Magdalenian carving of a horse head — Photo: musée des antiquités nationales
"Magdalenian art was splendid," Stephan Heidenreich confirms. Artistic representation regressed with the Federmesser groups "and all that remains is worked slate and scree."
Grimm believes that this loss of complexity ties in with climate change. Higher temperatures meant that the reindeer headed north, and forests grew in central Europe. Now, elk and red deer were on the menu. These animals live in small groups and thus did not offer enough food for the long-term. So people had to resettle more frequently, and they may have been more stressed. "The archeological sites are smaller," Grimm says. "You don't find big tent installations." People traveled in smaller groups, and were more mobile than they had previously been. There was less time for art.
But another interpretation is also possible: that the Federmesse groups painted their finest art on wood, of which they had plenty. These works would not have survived because the wood would have decomposed. "We don't know what wonderful art forms, like song or story-telling, existed outside the archeological finds," says Brian Wygal of Adelphi University in New York.
But the big question is how these people dealt with climate change, particularly the sudden jumps in temperature. Because 14,000 years ago it got really cold again in Europe. Deer and elk disappeared, and suddenly the reindeer were back. Some sites indicate that there was marked malnutrition. Wygal is convinced that "it was a tumultuous age, with rapid change between hot and cold. While some cultures adjusted well and flourished, others may have failed." In Europe there are only a few sites from these climatically turbulent times, so their interpretation will keep researchers busy for a long time.
Heidenreich suspects, however, that the hunters and gatherers "were in a good position to deal with climate change." Many researchers believe that the Federmesser groups hunted with bows and arrows — marked progress from what had come before. When an archeological culture disappears, as the Magdalenian one did after the Ice Age, it doesn't mean that the people disappeared, Heidenreich notes. "You have to see it as a kind of flowing transition, a coming and going."
In the end, the settling of Europe is the best proof that the climate change cultures braved environmental change by completely readapting their technology, art and lifestyle.