A Critical Orbiting Eye Will Fade From a Lack of Earthly Competence
Over the next decade the residents of Earth will need to keep a critical eye on its surface--to keep track of greenhouse warming, forest damage from acid rain, desertification and tropical deforestation. We can deal with global environmental problems only if we have accurate information about whether--and where--those problems are getting better or worse.
The good news is that we have that information. The Landsat program has been sending us satellite images of Earth’s surface since 1972. Landsats 4 and 5, in orbit now, provide a complete global picture every two weeks. The wavelengths they scan are uniquely suited for detecting changes in vegetation. Thanks to them we have a historical record of the global environment and a sensitive early warning system to spot trouble.
The bad news is that the National Oceanic and Atmospheric Administration (NOAA) is planning to stop collecting Landsat data after March 1, and will abandon the satellites on April 1. The reasons for this move began with the Reagan Administration’s determination to privatize government functions and end with an unwillingness to spend $26 million--out of a total government budget of more than $1 trillion.
The Reagan idea was that Landsat could pay for itself by selling Earth images to commercial clients such as oil companies, which use them for exploration. Responsibility for Landsat was transferred from the National Aeronautics and Space Administration to NOAA, in the Department of Commerce, which created the Earth Observation Satellite Co. (Eosat), a private corporation managed by a coalition of aerospace firms. Eosat’s job was to market Landsat images.
Oil companies, it turns out, only need one good Earth scan every eon or so. The primary users of Landsat--scientists studying environmental changes, Third World countries doing basic resource inventories--were priced out of the market when Eosat quadrupled the charge for an image. Eosat management squandered money, marketed poorly and became a continuous drain on NOAA’s budget. Finally Congress, disgusted with Eosat inefficiency and in a mood for budget cutting, decided to pull Landsat’s plug. The money saved will reduce the federal deficit but .002%--or about the cost of Bush’s inaugural fete.
If after March 1 the stream of data coming from Landsat is no longer received, a 17-year history of planetary information will be interrupted.
We have other Earth-scanning satellites in the sky; so do France, the Soviet Union and other nations--and the Japanese are about to put one up. All these nations have “open skies” policies; their data is available to us. But only Landsat reads the Earth through a set of high-resolution, near-infrared and shortwave spectral bands especially suited to provide information about stresses in the planet’s vegetation.
Prof. Barry Rock and his research team at the University of New Hampshire use Landsat to watch the effects of acid rain and air pollution on the New England forest. They correlate the wide sweep of satellite information with more thorough but scattered ground studies. The acid rain study is itself worth the price of Landsat, but now and then the researchers find the satellite images not only predictably useful, but unexpectedly so.
Rock has found “acid rain false alarms,” unusual spots of forest dieback that turned out upon ground inspection to be not acid rain damage but toxic dump sites. Through the satellite images, he finds not only the dumps but monitors whether vegetation returns after they are closed.
Late last June the Northeast suddenly realized it had a massive problem with a hitherto uninteresting insect called the pear thrip. It began rampaging through the sugar-maple forests, defoliating as it went. By the time authorities began to ask insistent questions, the insect’s feeding cycle was over, the trees were putting out a late crop of leaves and the infestation was hard to map. But Rock could call up Landsat images from June 5, when the trees were maximally defoliated, and another set of comparison images from a previous, uninfested June. He could chart the insect’s spread with great accuracy, to provide a basis for predicting its possible future advance.
These stories show the three essential features of Landsat: Its fine resolution (to 30 meters); its use of wavelengths particularly sensitive to vegetation under stress, and the continuity of its record. No one knew in advance that we would want to trace a New England pear thrip outbreak, the ecological damage from Chernobyl, the burning of the forest in Amazonia, the drought in the Midwest or the effects of the ozone hole on plants in Argentina.
Landsats 4 and 5 have both exceeded their planned lifetimes. Satellites have a good record of doing that, however, and there is some hope that these might last until Landsat 6 is launched (now scheduled for 1992)--if the nation recovers its senses and decides, quickly, to keep them alive.
There are many ways to do that. Cancel Eosat and give NOAA a proper budget for maintaining Landsat. Or give the responsibility back to NASA. If we truly can’t afford to provide the monitoring of Earth for all other nations of the world in the long run, at least keep these already-paid-for earth monitors functioning as long as possible.
It makes no economic sense to shut down Landsat. Doing so would be a scientific disaster. And at this time of great environmental uncertainty, it could be an ecological disaster too.
