Lonnie Thompson (b. 1948), is a paleoclimatologist and Distinguished University Professor in the School of Earth Sciences at The Ohio State University. He has achieved global recognition for his drilling and analysis of ice cores from mountain glaciers and ice caps in the tropical and sub-tropical regions of the world. He and his wife, Ellen Mosley-Thompson, run the ice core paleoclimatology research group at the Byrd Polar Research Center.
Lonnie Thompson was born July 1, 1948 in Huntington, West Virginia. He obtained his undergraduate degree from Marshall University, where he majored in geology. He subsequently attended The Ohio State University where he received his M.S. and Ph.D. degrees in geology. In the 1970s, he was the first scientist "to retrieve ice samples from a remote tropical ice cap and analyze them for ancient climate signals." He created the ice core research program at Ohio State while still a graduate student there. In regards to the dedication required to attain this ice, one author writes:
In his efforts to obtain ice cores, Thompson has spent an enormous amount of time at elevations above 5,500 meters. High-altitude climbers typically tackle a peak by spending time in a series of camps at lower elevations to acclimatize and then making a final rushed push for the summit. But Thompson and his loyal band of colleagues, students and mountain guides spend literally months at a time working at altitude...
Thompson and his colleagues have managed to drill into tropical glaciers with nothing more to rely on than a combination of modest funding, low-tech equipment, ingenuity and sheer muscle power. Because the thin air at high altitudes precludes the use of helicopters, all of the drilling equipment and supplies must be carried up and down the slopes by yaks, mules, horses or humans...—Mark Bowen, Thin Ice
For comparison, the Everest lower base camp is at 5,380 m (17,700 ft) and the upper base camp is at 6,500 m (21,300 ft). (The mountain itself is 8,848 m (29,029 ft).) Rolling Stone magazine says that there is no person in the world that has spent more time above 18,000 feet than Lonnie Thompson..
His observations of glacier retreat (1970s–2000s) "confirm that glaciers around the world are melting and provide clear evidence that the warming of the last 50 years is now outside the range of climate variability for several millennia, if not longer." In 2001, he predicted that the famed snows of Africa’s Mount Kilimanjaro would melt within the next 20 years, a victim of climate change across the tropics. Return expeditions to the mountain have shown that changes in the mountain’s ice fields may signal an even quicker melting of its snow fields, which Thompson documented had existed for thousands of years. Thompson and his wife both served as advisers for the Academy Award-winning 2006 documentary An Inconvenient Truth, by Al Gore, Jr., and some of their work was referenced in the movie.
2002: Thompson was awarded the Vega Medal by the Swedish Society for Anthropology and Geography.
May, 2007: Thompson is named to receive the National Medal of Science.  This honor is the highest the United States can bestow upon an American scientist. It was presented to Thompson by President Bush in July 2007 (Award year 2005). 
Lonnie Thompson has been awarded 53 research grants from the NSF, NASA, NOAA and NGS and has published 165 papers. An abbreviated list of expeditions, grants, and publications can be found in his Ohio State curriculum vitae (PDF).
Some notable publications include:
WOSU Public Media profiled the Thompson's polar research in 2008 in a two video segments distributed nationally.