And yet the truth, often obscured by the fog of politics, is that the scientists are genuinely uncertain about how fast the warming is happening, what and how strong the negative effects will be, and how quickly those problems will begin showing up in your neighborhood.
That uncertainty has helped make them vulnerable to critics who have a long list of reasons for doubting virtually any science-based warnings, including the consensus hammered out by the United Nations Intergovernmental Panel on Climate Change that carbon-dioxide emissions must be reduced. Some contend the planet has been cooling since a period of unusual warmth in 1998. Some suggest wide temperature variations are natural. Some argue that the earth has processes that counteract any excess heat.
The Scripps Institution of Oceanography at the University of California at San Diego is heading one major effort to monitor the ocean temperature variations. Known as Argo, it is a worldwide system of some 3,500 electronic buoys that automatically submerge and resurface, constantly transmitting data on underwater temperatures into a computerized collection network.
Argo promises "one of the most important new data sets we're going to get in the near future," says Chris E. Forest, an associate professor of climate dynamics at Pennsylvania State University's main campus. "We're going to learn a lot, once we sort of pin down how much heat is going into the oceans."