Retreat of the Chacaltaya Glacier, Bolivia: 
Until 2004 the Chacaltaya Glacier hosted the only ski area in Bolivia, which at 5,300 meters was also the world's highest ski run. Chacaltaya Glacier has now melted almost entirely due to warming and skiing is no longer possible. The ski lift, indicated with a red line, had a length of about 800 m in 1940 and about 600 m in 1996. The red cross shows the position of the ski hut, which did not exist in 1940. The original location of the ski lift in 1940 is indicated with a black segmented line in subsequent years. 
Sources: IPCC Working Group II Fourth Assessment Report 2007; 1940 Servicio Aerofotográfico Nacional, Bolivia; 1982
Reinhardt & Jordan; 1996, 2005 Bernard Francou

May 16, 2008

Study Shows Human-Caused Climate Change Responsible for Global Impacts

First-ever survey of data shows human activity
linked to changes in diverse physical and biological systems


A vast array of physical and biological systems across the earth are being affected by warming temperatures caused by human activity, says a new Columbia study. These impacts include earlier leafing of trees and plants over many regions; movements of species to higher latitudes and altitudes in the Northern Hemisphere; changes in bird migrations in Europe, North America and Australia; and shifting of the oceans’ plankton and fish from cold- to warm-adapted communities. Based on an analysis of aggregated data, this study is the first to link observed global changes in diverse systems to human-caused, or anthropogenic, climate change. The study appears in the May 15 issue of the leading scientific journal Nature.


“Humans are influencing climate through increasing greenhouse gas emissions, and the warming world is causing impacts on physical and biological systems attributable at the global scale,” said lead author Cynthia Rosenzweig, a scientist at the NASA Goddard Institute for Space Studies and the Columbia Center for Climate Systems Research. Both are affiliates of the Earth Institute at Columbia University.

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