Andrew C. Revkin, New York Times environmental reporter, recently filed this series of articles from the Arctic, where he observed the work of scientists studying climate change. The reporting is even-tempered, extremely informative, and observant. His photographs alternately capture the eye-smacking beauty of the Arctic, and the challenges and incongruities of human presence in that landscape.

Embarking in a military cargo transport plane on May 17, he wrote:

The plane's cargo bay was easily big enough to hold a city bus, but in this case, along with the passengers and crew, held several pallets of scientific gear and supplies, an aging red Volkswagen minibus — and several perforated boxes loaded with softly cooing pigeons.

The pigeons and the VW were to be used in a research project of the Peregrine Fund, a private group, studying migratory patterns and populations of the fast-flying raptors.

But most of the people heading to Greenland this spring and summer are focused on the climate, past, present, and future.

There is no better place to understand all of those dimensions than Greenland, where an extraordinary volume of ice — a tenth of all the frozen fresh water on Earth — both contains clues to the past in its layers and, in its melting, could contribute to one of the costliest anticipated impacts of global warming.

Greenland is, after all, where scientists nearly 20 years ago first pierced the ancient two-mile-deep ice sheet and extracted slender cylinders providing a record of climate changes over 120,000 years. In so doing, they discovered some of the most compelling evidence that conditions could change abruptly sometimes in a matter of a decade. The two biggest upheavals came 8,200 years ago and nearly 12,000 years ago, sending the northern hemisphere into prolonged cold spells well after the last ice age had ended.

But this was not just about climate history. Greenland's ice could play a powerful role in shaping the impacts of future climate shifts, particularly if warming continues from building concentrations of heat-trapping greenhouse gases.