HR: 16:15h
AN: C44A-02 INVITED     [Abstracts]
TI: Low-latitude mountain glacier evidence for abrupt climate changes
AU: * Thompson, L G
EM: thompson.3@osu.edu
AF: Byrd Polar Research Center, The Ohio State University, 1090 Carmack Road, Columbus, OH 43210 United States
AU: * Thompson, L G
EM: thompson.3@osu.edu
AF: Department of Geological Sciences, The Ohio State University, Columbus, OH 43210 United States
AU: Mosley-Thompson, E S
EM: thompson.4@osu.edu
AF: Byrd Polar Research Center, The Ohio State University, 1090 Carmack Road, Columbus, OH 43210 United States
AU: Mosley-Thompson, E S
EM: thompson.4@osu.edu
AF: Department of Geography, The Ohio State University, Columbus, OH 43210 United States
AU: Lin, P
EM: lin.25@osu.edu
AF: Byrd Polar Research Center, The Ohio State University, 1090 Carmack Road, Columbus, OH 43210 United States
AU: Davis, M E
EM: davis.3@osu.edu
AF: Byrd Polar Research Center, The Ohio State University, 1090 Carmack Road, Columbus, OH 43210 United States
AU: Mashiotta, T A
EM: mashiotta.1@osu.edu
AF: Byrd Polar Research Center, The Ohio State University, 1090 Carmack Road, Columbus, OH 43210 United States
AU: Brecher, H H
EM: brecher.1@osu.edu
AF: Byrd Polar Research Center, The Ohio State University, 1090 Carmack Road, Columbus, OH 43210 United States
AB: Clear evidence that a widespread warming of Earth's climate system is now underway comes from low latitude mountain glaciers. Proxy temperature histories reconstructed from ice cores, and the rapidly accelerating loss of both the total ice area and ice volume on a near global scale suggest that these glaciers responding to increasing rates of melting. In situ observations reveal the startling rates at which many tropical glaciers are disappearing. For example, the retreat of the terminus of the Qori Kalis Glacier in Peru is roughly 200 meters per year, 40 times faster than its retreat rate in 1978. Similarly, in 1912 the ice on Mount Kilimanjaro covered 12.1 km$^{2}$, but today it covers only 2.6 km$^{2}$. If the current rate of retreat continues, the perennial ice fields may disappear within the next few decades, making this the first time in the past 11,700 years that Kilimanjaro will be devoid of the ice that shrouds its summit. Tropical glaciers may be considered ``the canaries in the coal mine'' for the global climate system as they integrate and respond to key climatological variables, such as temperature, precipitation, cloudiness, humidity, and incident solar radiation. A composite of the decadally-averaged oxygen isotopic records from three Andean and three Tibetan ice cores extending back over the last two millennia shows an isotopic enrichment in the 20th century that suggests a large-scale warming is underway at lower latitudes. Multiple lines of evidence from Africa, the Middle East, Europe and South America indicate an abrupt mid-Holocene climate event in the low latitudes. If such an event were to occur now with a global human population of 6.3 billion people, the consequences could be severe. Clearly, we need to understand the nature and cause of abrupt climate events.
DE: 3344 Paleoclimatology
DE: 1803 Anthropogenic effects
DE: 1827 Glaciology (1863)
DE: 1600 GLOBAL CHANGE (New category)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting