Thompson is one of the world’s foremost authorities on paleoclimatology and glaciology. For over 40 years, he has led 60 expeditions where they conduct ice-core drilling programs in the Polar Regions as well as on tropical and subtropical ice fields in 16 countries including China, Peru, Russia, Tanzania and Papua, Indonesia (New Guinea). He and his team from the Ohio State University have developed light-weight solar-powered drilling equipment for acquisition of histories from ice fields in the tropical South American Andes, the Himalayas, and on Mount Kilimanjaro in Tanzania. 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: 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 who 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 incorrectly 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. == Personal life ==