Oceanic findings confirm warming.

• Author: Dunn, Seth
• Position: Brief Article

The world's oceans have warmed dramatically over the last four decades, according to research published in the March 24 issue of Nature. The new findings help resolve a disparity between the atmospheric temperature increases projected by climate models and those observed at the Earth's surface, adding credibility to the belief that much of the past century's warming has been human-induced. The discovery also guarantees that more atmospheric warming lies ahead, and suggests that the climate may be more sensitive to greenhouse gases than previously thought.

For years, climate modelers have been confronted with an apparent incongruity between the increases in temperature projected in their models and the relatively modest warming witnessed over the last several decades. The modelers have noted that oceans would absorb some of the heat trapped by greenhouse gases in the atmosphere, delaying but not stopping an eventual warming. But oceanographers have experienced difficulty in ascertaining whether this "missing warming" had indeed occurred in the ocean, having been hampered by patchy records of deep-ocean temperature.

To fill this research gap, a team of physical oceanographers from the National Oceanic and Atmospheric Administration (NOAA) engaged in a painstaking seven-year collection of millions of old deep-ocean temperature measurements made by hundreds of independent observers all over the world during the last 50 years. These neglected data had never before been compiled into a database; unlike meteorologists, oceanographers have not relied on a coordinated, global network for their observations. Pulled together, however, the rediscovered records enabled the scientists to construct "oceanic fever charts."

With some 5 million profiles of ocean temperature finally assembled, the NOAA scientists were able to...