A Climate Scientist Battles Time

http://www.nytimes.com/2012/07/03/science/earth/lonnie-thompson-climate-scientist-battles-time.html

"Dr. Thompson became one of the first scientists to witness and record a broad global melting of land ice. And his ice cores proved that this sudden, coordinated melting had no parallel, at least not in the last several thousand years.

In 1974, with $7,000 from the National Science Foundation, Dr. Mercer and Dr. Thompson led a scouting party to Quelccaya, on a volcanic plain 18,000 feet above sea level. They confirmed that annual layering caused partly by seasonal dust could be seen in the ice.

After a series of frustrated attempts to drill through the ice, including one involving a helicopter, Dr. Thompson resorted to mules, horses and donkeys to mount a 1983 expedition that drilled through 537 feet of ice with a solar-powered drill.

The results were startling. The ice record stretched back 1,500 years, and it recorded huge oscillations in the climate of the region — intense dry spells alternating with wet spells. Vast lakes had come and gone in the valleys, the dust from their dried-up beds leaving chemical imprints in the ice. The record also showed changes in water chemistry similar to those seen at the poles, leading Dr. Thompson to infer major temperature swings in the tropics.

... One of the greatest achievements of modern climate science was the recovery of ice cores in Antarctica that allowed a detailed reconstruction of the earth's climate for the past 800,000 years. Dr. Thompson suspects an even longer record could be recovered by drilling at the right spot in Tibet."