Chemical clues in the sections of ice enabled researchers to reconstruct a record of temperature changes going back about 15,000 years, to a time when the last ice age was coming to an end.
Twice before in the past 2,000 years — around A.D. 400 and A.D. 1500 — the rate of warming has approached the modern one, Mulvaney said. The current warming trend began about 600 years ago, accelerating in the past 50 to 100 years, bringing the peninsula close to its post ice-age highs.
Warmth means melt
Warming isn't just important for its own sake. While the thick layers of ice that extend from the frozen land have been stable for thousands of years, in the last 30 years rapid collapses, in which the ice shelves disintegrate into the sea, have begun, according to the U.S. Snow and Ice Data Center. [Antarctic Album: An Expedition Into Iceberg Alley]
In 1995, the northernmost portion of the Larsen Ice Shelf, about 770 square miles (2,000 square kilometers) collapsed, forming small icebergs. After retreating for some time, the nearby Prince Gustav Ice Shelf collapsed the same year.
Scientists have wondered if the loss of ice shelves and rising temperatures on the Antarctic Peninsula are the result of natural cycles or if humans' alterations to the environment, including the ozone hole of Antarctica, are responsible. The results of the study don't provide an answer to this question, but they do offer insight into the pre-Industrial temperature history and how it related to the state of the region's ice shelves.