June 26, 2006: Study Finds Evidence that Glaciers are Melting at a Rate Unprecedented in the Last 5,200 Years

A study published in the Proceedings of the National Academy of Sciences (PNAS) argues that “the present warming and associated glacier retreat are unprecedented in some areas for at least 5,200 years.” As evidence, it notes the widespread melting of mountain glaciers, the uncovering of plants that were buried thousands of years ago, and a change in the chemical isotopes of ice cores taken from seven mountain glaciers over the past 30 years, including the Huascaran and Quelccaya ice caps in Peru, the Sajama ice cap in Bolivia, and the Dunde and Puruogangri ice caps in China. According to the study’s authors, the ice samples also indicate that there was a sudden cooling of the climate five millennia ago. [Independent, 6/27/2006] Additional evidence of the sudden climate change has come from Mount Kilimanjaro; African lakes; Greenland and Antarctic ice cores, lead author Lonnie Thompson notes in an interview with the Washington Post. “There are thresholds in the system,” he says. “There is the risk of changing the world as we know it to some form in which a lot of people on the planet will be put at risk.” [Washington Post, 6/27/2006]