Under a White Sky

In its broad outlines, Dansgaard’s reading of the Camp Century core confirmed what was already known about climate history. The most recent ice age, known in the United States as the Wisconsin, began roughly a hundred and ten thousand years ago. During the Wisconsin, ice sheets spread over the northern hemisphere until they covered Scandinavia, Can

This has been a book about people trying to solve problems created by people trying to solve problems. In the course of reporting it, I spoke to engineers and genetic engineers, biologists and microbiologists, atmospheric scientists and atmospheric entrepreneurs. Without exception, they were enthusiastic about their work. But, as a rule, this enthu

the ice sheet’s surface. That summer—a record-breaker—Greenland shed almost six hundred billion tons of ice, producing enough water to fill a pool the size of California to a depth of four feet.

“The current Arctic is experiencing rates of warming comparable to abrupt changes, or D–O events, recorded in Greenland ice cores,” a team of Danish and Norwegian scientists recently reported. Since the melt process is self-reinforcing—water is dark and absorbs sunlight, while ice is light-colored and reflects it—there’s widespread concern that Gre

As with temperatures, sea levels have in the past varied dramatically. At the end of the Wisconsin, as the great ice sheets were breaking up, there were periods when they rose at the astonishing rate of a foot a decade. (It’s been proposed that one of these “meltwater pulses” inspired the account of the deluge in Genesis.) Obviously, our ancestors

Scientists are still trying to puzzle out what caused the wild temperature swings first glimpsed in the Camp Century core. One hypothesis is that they are related to a loss of sea ice in the Arctic, which is worrisome, given that global warming is causing a loss of sea ice in the Arctic. But even putting aside the possibility of a human-induced D–O

Over the next four decades, five more cores were extracted from different parts of the ice sheet. Each time, the wild swings showed up. Meanwhile, other climate records, including pollen deposits from a lake in Italy, ocean sediments from the Arabian Sea, and stalagmites from a cave in China, revealed the same pattern. The temperature swings became

Andy Parker is the project director for the Solar Radiation Management Governance Initiative, which works to expand the “global conversation” around geoengineering. His preferred drug analogy for the technology is chemotherapy. No one in his right mind would undergo chemotherapy were better options available. “We live in a world,” he has said, “whe

“The melting of the Antarctic ice cap would raise sea level by four hundred feet,” the report noted. Even if the process took a thousand years to play out, the oceans would “rise about four feet every ten years,” or “forty feet per century.”