-- Ceci Connolly
Data Support Warming Signs
New measurements from the world's oceans give the most compelling evidence yet that man-made global warming is underway and hint at a more dramatic and sudden climate change in the future.
Two sets of ocean readings presented at the meeting solidify the scientific underpinnings of global warming and point to an increased chance for a side effect fictionalized in last year's movie "The Day After Tomorrow," in which global warming triggers a new ice age in the Northern Hemisphere.
"The debate is no longer whether there is a global warming signal," said Tim Barnett, a marine physicist at Scripps Institution of Oceanography who analyzed 9 million ocean-temperature and salinity readings. "The debate is what are we going to do about it."
The data show that the world's oceans have heated up just as predicted in computer models, and, more ominously, that massive amounts of fresh water from melting Arctic ice are seeping into the Atlantic Ocean, threatening to trigger a climate crisis.
What scientists have found could cause parts of the eastern United States to cool by several degrees, according to new calculations described by Ruth Curry, a scientist at the Woods Hole Oceanographic Institution. The same worst-case "Day After Tomorrow" scenario is one that a 2003 Pentagon analysis said "would challenge United States' national security in ways that should be considered immediately." A 2002 National Academy of Sciences study cited concern about it, too.
Curry found that between 1965 and 1995, about 4,800 cubic miles of fresh water -- more than Lake Superior, Lake Erie, Lake Ontario and Lake Huron combined -- melted from the Arctic region and poured into the normally salty northern Atlantic.
If it continues, the increased influx of fresh water eventually could shut down the "conveyor belt" of ocean currents that helps regulate air and water temperatures, abruptly changing the climate.
-- Knight Ridder Tribune
