Chester Langway's laboratory holds six miles of ice that reveal volumes about Earth's past and, perhaps, its future.

"It's all there . . . frozen in time," said Langway, whose University of Buffalo lab contains the nation's store of ice core samples from Greenland and Antarctica - a record of natural history stretching 150,000 years.Ice, formed as layer after layer of snow fell and was compacted, provides a seasonal record more detailed than tree rings or sea floor sediments, he said.

Using techniques Langway pioneered, researchers have begun analyzing ancient ice molecules. Oxygen isotopes record yearly temperature variations. Dust levels show prehistoric volcanic activity. Tiny bubbles of air give direct evidence of what the atmosphere was like thousands of years ago. The water that makes up the ice can indicate natural levels of elements such as lead, cadmium, sulfur and chlorine, and can be used to gauge the effect industrial activity.

The ice cores, six miles of them, are kept in 4-inch-diameter, meter-long aluminum cylinders in a refrigerator at 10 degrees below zero. Technicians in parkas, their beards and eyebrows frosted, prepare the ice for Langway's experiments and for shipment to scientists at another universities.

"We're just beginning to unlock the secrets in the ice," said Langway, 59, a geology professor who has a mountain named after him in Antarctica. He sometimes jokes about spending more than five years in polar regions researching ice - "Man is the only animal stupid enough to wander about out there" - but he clearly believes in his work.

Particularly in some controversial research involving gases trapped in the ice cores. Scientists have noted a sharp increase in carbon dioxide in the last 150 years since the beginning of the industrial age, part of the debate about the "greenhouse effect," global warming from the buildup of heat-trapping gases from industrial emissions and deforestation.

"A full understanding of how the planet works can't be obtained without considering the ice," Langway said. Changes in the level of carbon dioxide in the past have coincided with changes in the climate. Levels of the gas may even be part of a mechanism that causes ice ages and global warming trends.

There have been seven or eight times when the Earth's climate changed drastically, with glaciers enveloping the continents and then retreating, he explained. Carbon dioxide levels were very low 20,000 years ago, when the Earth was at its coldest. About 13,000 years ago, atmospheric carbon dioxide began to increase. About 10,000 years ago, the ice began to retreat amidst violent weather changes probably brought about by increase volcanic activity.

Some scientists think the Earth may soon undergo a major climate change brought on by pollution. They have developed computer models showing disastrous consequences such as droughts and rising ocean levels over the next 50 years.

Langway, however, is emphatic about not drawing conclusions for the future from current ice core research. "You can speculate like crazy, but we just haven't done enough research to have all the answers."

One problem is a shortage of ice. Greenland's ice sheet is the size of the United States east of the Mississippi, and Antarctica is 10 times larger; even six miles of cores in storage is "like putting a teacup in Boston and one in Florida and trying to figure out what's been going on in between," he said.

Langway will take part in two international expeditions next year that will drill in Greenland and Antarctica - the first new drilling since 1981.