of lakes dot the marshy Arctic tundra regions. Now, in the
latest addition to the growing body of evidence that global
warming is significantly affecting the Arctic, two recent
studies suggest that thawing permafrost is the cause of two
seemingly contradictory observations both rapidly growing and
rapidly shrinking lakes. Thawing permafrost is altering the
lakes that dominate Arctic landscapes, such as this one in
western Siberia. Courtesy of Laurence C. Smith. The first study
is a historical analysis of changes to 10,000 Siberian lakes
over the past 30 years, a period of warming air and soil
temperatures. Using satellite images, Laurence Smith, a
geographer at the University of California, Los Angeles, and
colleagues found that, since the early 1970s, 125 Siberian lakes
vanished completely, and those that remain averaged a 6 percent
loss in surface area, a total of 930 square kilometers. They
report in the June 3 Science that the spatial pattern of lake
disappearance suggests that the lakes drained away when