Climate Change Threatens Archeological Treasures

Climate Change Threatens Archeological Treasures

We have all been made aware of the present and future changes to our environment resulting from global warming. Less well known, however, is the impact upon our archeological heritage. A United Nations panel of 1000 experts on climate science recently estimated that the world’s temperature has risen approximately two degrees in the past century. The main cause has been an increase in carbon dioxide that traps heat in the earth’s atmosphere. Among the observable results has been a rise in the world’s oceans of four inches. Also, weather patterns have become less predictable and more extreme. The UN experts predict that ocean levels will rise another four inches over the next one hundred years. A worst-case scenario involves an increase of ten degrees in global temperatures. This would cause ice caps to melt even more rapidly than they are at present and sea levels to rise more than three feet.

Around the world, archeologists are operating on the premise that global warming will not be reversed, or stopped. Their concern is with the protection of archeological sites, both excavated and unexcavated.

In Kazakhstan, Scythian burials have remained frozen for thousands of years. Hotter summers are causing the human remains they contain to decay, in some cases faster than archeologists can get to them to study and preserve. Three thousand years ago, Scythian nomads ruled the Eurasian steppes from the edges of the Black Sea (photo above) in the west to China in the east. They buried their dead in huge grave mounds called kurgans. These have been important sources of information for archeologists studying how this nomadic culture spread, thrived, and faded away around 200 B.C. Kurgans are found from Ukraine to Kazakhstan. The best preserved are those in the Altai Mountains (photo below) on the edge of the vast Siberian permafrost region. Many of these graves have been frozen for millennia. Archeologists have found well-preserved mummies in the kurgans, often with their clothing, burial goods, and horses intact. The material culture of the Scythians is thus revealed.


The Altai Mountains, however, are not as cold as they once were. The glaciers that covered the Altai slopes are receding and even disappearing. For the first time in 3,000 years, the Scythian corpses in the kurgans are in danger of thawing and decaying. An international effort to save the frozen tombs has included the use of satellite photos and ground surveys to map and list the region’s kurgans. A priority is identifying the kurgans that may still have permafrost underneath them. The next step will be to determine how to keep the grave mound cool in order to preserve them for future researchers. Proposals range from reflecting sunlight away from the tombs by painting them white to stabilizing the underground temperature by installing thermo-pumps.

Peru is known as the home of the Inca and other civilizations. It is also a place strongly affected by El Niño. Every seven to ten years, Pacific Ocean currents shift, changing weather patterns from Australia to California. In Peru, El Niño brings warmer water and heavy rainfall along the coast. Peru’s deserts ordinarily receive just over an inch of rain per year. In 1998, the last severe El Niño season, the region received 120 inches, which caused severe flooding. Water damages exposed archeological sites, especially those located on rivers or on easily eroded slopes.

Chan Chan (photo above) is an eight-miles-square city that dates back 1000 years. Made of mud brick, its pyramids and palaces have been threatened by erosion. In the past twenty years, the site has deteriorated steadily. If, as researchers believe, global warming will make El Niño effects more frequent, the resultant increased rainfall will increase the potential for the ancient city’s destruction.

In normal summers, Greenland’s northern and eastern coasts should be ringed by an ice belt thirty to forty miles wide. The drifting ice acts like a shock absorber, lessening the impact of the North Atlantic. In the past five years, the sea ice has all but disappeared (photo above). This leaves Greenland’s coast open to the impact of storm surges originating hundreds of miles away. The effect on the island’s archeological heritage has been severe. Hardest hit have been sites associated with the Thule culture, people closely related to the Inuit of northern Canada who first migrated to Greenland around 2,000 years ago. The Thule were skilled hunters and whalers whose villages were built near the shore. Today, Thule houses, made of stone and turf with whale-bone rafters, are disappearing quickly, along with buried tools and artifacts. Older sites along the coast are also in danger. As the Arctic warms, archeologists fear the frozen turf that covers Qeqertasussak, a 4,500-year-old settlement where evidence of the earliest habitation of Greenland was found, may be melting. The knowledge the site contains will be lost with the ice.

Global warming threatens archeological investigation all over the world. If knowledge of the past is necessary to better understand the present and to anticipate the future, the consequences of this loss will be significant.