Coral Davenport, Josh Haner, Larry Buchanan and Derek Watkins (The New York Times):
“We scientists love to sit at our computers and use climate models to make those predictions,” said Laurence C. Smith, head of the geography department at the University of California, Los Angeles, and the leader of the team that worked in Greenland this summer. “But to really know what’s happening, that kind of understanding can only come about through empirical measurements in the field.”
For years, scientists have studied the impact of the planet’s warming on the Greenland and Antarctic ice sheets. But while researchers have satellite images to track the icebergs that break off, and have created models to simulate the thawing, they have little on-the-ground information and so have trouble predicting precisely how fast sea levels will rise.
Scientists know that the melting of Greenland is accelerating. As the temperature rises, large lakes form on the surface of the ice, which in turn create a network of rivers.
“The rivers melt down faster than the surrounding ice, like a knife through butter,” Dr. Smith said.
The rivers then flow down into giant holes in the ice, called moulins, which drain through tunnels in the ice sheet and out into the ocean.
“The ice sheet is porous, like Swiss cheese,” Dr. Smith said. “We didn’t know that until this year.”
Their research could yield valuable information to help scientists figure out how rapidly sea levels will rise in the 21st century, and thus how people in coastal areas from New York to Bangladesh could plan for the change.
Each year, the federal government spends about $1 billion to support Arctic and Antarctic research by thousands of scientists like Dr. Smith and his team. The agency officials who receive that money from Congress, including the directors of the National Science Foundation, NASA and the National Oceanic and Atmospheric Administration, say the research is essential for understanding the changes that will affect the world’s population and economies for more than a century.
But the research is under increasing fire by some Republican leaders in Congress, who deny or question the scientific consensus that human activities contribute to climate change.