Word: ices
(lookup in dictionary)
(lookup stats)
Dates: during 1990-1999
Sort By: most recent first
(reverse)
This process may already have started. Ted Scambos, an analyst at the National Snow and Ice Center in Boulder, Colorado, looks at a satellite image and says, "I see an ice sheet in the process of collapse." But before anyone rushes to sell off property in Florida, he hastens to add that there are still too many unknowns and that any change could take thousands of years...
...poet Robert Frost asked whether the world would end in fire or ice. Four years ago, Taylor and other geophysicists found evidence that the answer may be both. The message, extracted from an ice core taken in Greenland, at the opposite end of the earth, was that climate can change dramatically over short periods of time. Roughly 11,500 years ago, Greenland suddenly chilled, and then 1,500 years later, it suddenly warmed. The speed of the last change--an 18[degree] warming in some places in as little as three years--was fast enough, a meteorologist wryly commented...
Scientists have assumed that any change caused by humans would occur over many decades. They are no longer so sure. As climatologist Peter deMenocal put it, "When I began my Ph.D. in 1986, the conventional wisdom was that it took 1,000 years to end an ice age; in '91 that figure was lowered to 100 years, and then just two years later, Richard Alley at Penn State published a paper about climate changing in two to five years...
...climate change brings about a large rise in sea level, the principal immediate cause will be the collapse of the West Antarctic ice sheet. WAIS is the world's last remaining marine ice sheet (meaning that it sits on the ocean floor rather than floats). It is so big that volcanic eruptions at its bottom only rarely cause a dimple on its surface. Marine ice sheets persist only as long as they have enough mass to squeeze out underlying seawater, which makes them inherently unstable. Should this ice sheet collapse or float free, as other marine ice sheets have done...
Also vulnerable is the floating apron of sea ice that surrounds Antarctica. During the winter, this apron effectively doubles the continent's size, then in summer it shrinks 80%. The interaction of deep ocean currents and sea ice is crucial to the vast "conveyor belt" that redistributes the sun's heat around the globe. For all its importance, however, it is on average less than 2 ft. thick, and its stability depends on a precarious balance of factors ranging from air temperature to the salinity and temperature of the water...