PSU Magazine Summer 1989

Earth's fragile balance-------------------------- Drilling for • air K eith Mountain is an archaeologist of sorts, but instead of looking for bones or stone carvings, he travels the world in search of ancient air. A new recruit in PSU 's Department of Geography, after having worked since 1980 at Ohio State University, Mountain is looking for the kind of air Stone Age men and women breathed. Or that Christopher Columbus breathed. Or Napoleon. By doing so, he is looking for answers to questions such as Is the Earth undergo– ing a massive warming due to the greenhouse effect? What effects will it have on currents, precipitation , the polar ice caps? Are we in danger? He does this by taking ice core samples from glaciers throughout the world . Ice, he said , is among the most reliable ar– chives of the world's air. As snow falls, air becomes trapped , and as the snows become compressed through subsequent snowfalls, the air is locked into the resulting ice in the form of tiny bubbles. By digging down through hundreds of years of snowfalls, scientists such as PSU 4 Mountain can obtain as clear a record of what the world was like in centuries past, much like the observation a botanist makes from tree rings, or a geologist makes from stratified earth . "The nice thing about ice cores is they 're all over the world. You have a uniform data base that is global ," said Mountain, who for the past several years has been trying to recreate the climate of the tropics by studying ice caps in the Peruvian Andes. Recently he made drill– ings in central China, and he has done other testing in Antarctica, Greenland , Bolivia and Ecuador. A major objective in such drillings is to find out how the level of carbon dioxide on Earth has changed throughout time. Much of the scientific community believes that the Earth is quickly warming to dangerous levels because of an ever– growing amount of carbon dioxide and other gasses that have been released into the atmosphere since the beginning of the Industrial Revolution . Geography professor Keith Mountain Mountain performs on-site meteorological analyses to put on record the conditions the ice exists in at the time of testing. It is an important role, since most of the drilling sites are in remote areas with no other weather record. Once it has been established, scientists use it as a basis for comparison when they look in– to the layers left by previous years. Mountain has clearly seen, through the ice samples, that the Earth's climate is changing. But as yet he doesn't know the reasons, the magnitude or the rates of change. " It's not a question of do we have a greenhouse effect - we always have had one. But are we upsetting the natural balance?" he said . Even with unanswered questions, ice cores show a more promising way of find– ing out the answers than other scientific methods, such as analyzing fossilized pollen . But the conditions have to be right . For one, samplings must be taken from what Mountain calls "a significant block of ice" - one that is old, and fairly well pre– served. The ice in the Cascades has too much deterioration and is unsuitable. But the glacial ice that Mountain tested in Peru was intact enough to give a sequential record of seasons going back 1,600 years. For another, scientists need glaciers that give a true reflection of the global at– mospheric system. It's not good enough to only test in polar regions, even though Antarctica can yield 100,000-year-old records, because it doesn't reveal seasonal changes nearly as well as samples taken from Europe or South America. It may well be that the climatic changes going on in the world today are among the most dramatic in history, but for scientists such as Mountain, there are too many unanswered questions. He said the overall warming of the Earth may not be as important as regional warming, such as at the equator or in the polar regions. If one region warmed faster than the Earth as a whole, there could be vast changes in winds, sea currents, and precipitation that could make for a world much different than we know today. He's hoping the solution to the puzzle lies in the tiny bubbles imbedded in ice. D