Lonnie G. Thompson, 2001. "Stable Isotopes and their Relationship to Temperature as Recorded in Low-Latitude Ice Cores", Geological Perspectives of Global Climate Change, Lee C. Gerhard, William E. Harrison, Bernold M. Hanson
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The potential of stable isotopic ratios (18O/16O and 2H/1H) in mid- to low-latitude glaciers as a modern tool for paleoclimate reconstruction is reviewed. To interpret quantitatively the ice-core isotopic records, the response of the isotopic composition of precipitation to long-term fluctuations of key climatic parameters (temperature, precipitation amount, relative humidity) over the given area should be known. Furthermore, it is important to establish the transfer functions that relate the climate-induced changes of the isotopic composition of precipitation to the isotope record preserved in the glacier. This paper will present long-term perspectives of isotopic composition variations in ice cores spanning the last 25,000 years from the mid- to low-latitude glaciers. The δ18O records from the far western Tibetan Plateau suggest temperatures as warm as today occurred approximately 3000 years ago. However, δ18O records from the Himalayas and the eastern side of the Tibetan Plateau confirm that the twentieth century is the warmest period in the last 12,000 years. In the South American Andes on Huascarán, δ18O records suggest temperatures as warm as those of today occurred 5000 years ago.
All the tropical glaciers for which data exist are disappearing. The evidence for recent and rapid warming in the low latitudes is presented and possible reasons for this warming are examined. The isotopic composition of precipitation should be viewed not only as a powerful proxy indicator of climate, but also as an additional parameter for understanding climate-induced changes in the water cycle, on both regional and global scales.