If James E. Hansen of the NASA Goddard Institute for Space Studies in New York was right in 1997 saying that the earth is absorbing about 0.5 watt per square meter of sunlight more than it is emitting back to space, then where is the heat going? Hansen speculated it was probably in the oceans. Support came in 2000 from Sydney Levitus of the National Oceanographic Data Center in Silver Spring, Md:
That knowledge inspired Levitus and his colleagues seven years ago to launch a United Nations-sponsored global search?and-rescue operation for ocean data. The team?s primary goal was to dig up every single temperature measurement they could find for the top 3,000 meters of the ocean, enough water to engulf a skyscraper seven times as tall as the World Trade Center. They knew that the deeper they looked, the more convincing any emerging temperature trends would be.What?s more, that amount of warming accounts for a majority of Hansen?s "missing heat."
Numbers came in from all over the world. When the British Royal Navy told Levitus that it had hundreds of thousands of index cards of hand-written temperature profiles stashed away in a musty basement, the oceanographer jumped at the chance to add them to his growing database. He didn?t have to go far. Officials loaded a ship with some 100 metal file drawers full of the cards and sent them across the Atlantic. His team also uncovered unexpected measurements from World War II at the Scripps Institution of Oceanography in San Diego and rare numbers from the icy seas around Russia and Norway in an obsure book tucked away in the New York Public Library.
When they put the millions of numbers they gathered together with several million more that already existed, they discovered that the Pacific, Atlantic and Indian oceans combined warmed an average of 0.06 degree Celsius between 1955 and 1995.
Reference: ScientificAmerican.com April 17, 2000