The end of the cold war may nothave produced a peace dividend,but it could still produce a trea-

sure trove of data. A high-level commit-tee of scientists is pioneering an eÝortto extract vital environmental measure-ments from classiÞed information cur-rently being gathered by spy satellitesand other sensors. The potential utilityof this information far exceeds that ofthe spy satellite pictures from the 1960sthat President Bill Clinton ordered de-classiÞed this past February. Such ac-cess could permit precise assessmentsof deforestation and of possible indica-tors of global warming.

The committee studying the secretdata is called Medea, after the sorceressof Colchis in Greek mythology. Medeahelped Jason of the Argonauts steal the

Golden Fleece and became his wife. Ja-son is, in turn, the name taken by an-other group of scientists that has formany years provided secret advice tothe government on national security is-sues. (Medea and Jason are united inthe person of a shared representativefrom the Central Intelligence Agency,Linda Zall.)

Medea, established in 1993, is the de-scendant of an environmental task forceset up by the CIA in 1992. The initiativecame about in response to a requestfrom then Senator Al Gore of Tennes-see that the agency assess what data itcould make available to researcherswithout undermining secrecy. The taskforce played a key role in persuadingthe CIA and other agencies to declassi-fy the 800,000 photographs taken by

reconnaissance satellites between 1960and 1972. But although the former So-viet Union was well covered, many ar-eas of scientiÞc interest were not pho-tographed at high resolution.

The best images from these early setshave a resolution of about two meters,better than the 15-meter resolution ofLandsat. The present generation of spysatellites, however, is widely believedto resolve objects less than 15 centime-ters across. Medea was founded whenit became clear to the task force thatenvironmental science and intelligencegathering could each gain from the oth-erÕs expertise in the design of sensorsand the interpretation of data.

Medea is now wrestling with how toshare with scientists measurements ex-tracted from contemporary as well asarchived intelligence. The main stickingpoint is the sensitivity of informationabout when and where images were ob-tained, says JeÝrey Dozier of the Uni-versity of California at Santa Barbara.Such knowledge might allow an adver-sary to calculate the orbits of satellites,which would then make it possible tohide sensitive equipment by conceal-

28 SCIENTIFIC AMERICAN July 1995

TECHNOLOGY AND BUSINESS

Environmental SecretsMedea brings intelligence in from the cold

Antarctica is heating up, and the evidence is in the ice—or at least in its melt. One satellite image from this

past January (left ) shows the spidery-looking James RossIsland surrounded by water (top right ): ever since the firstmaps were made 100 years ago, it has been connected tothe Antarctic peninsula by an ice shelf. The image alsoshows the peninsula, composed of a chain of mountains(lower left to upper right ), surrounded by dark patches ofsea; the gargantuan Larsen ice shelf appears at the lowerleft. A satellite image taken shortly after, in February (right ),

documented further changes. The ice shelf has retreated;a 50-mile-long iceberg has calved; and the northernmostpart of the shelf, just above the center of the picture, hasdisappeared, creating a plume of ice rubble.

Other Antarctic ice shelves are also retreating, and “theyare all ones we said would be sensitive to climatic change,”notes David G. Vaughan of the British Antarctic Survey.Vaughan says the west side of Antarctica has warmed 2.5degrees Celsius over the past 50 years. But any link withglobal warming is unproved, he cautions. —Tim Beardsley

ItÕs Melting, ItÕs Melting

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Copyright 1995 Scientific American, Inc.