Mission to Planet Earth Takes Off

SEEING ourselves from the perspective of space can be shocking. For example, some 180 experts attending the first biomass burning conference last month in Williamsberg, Va., conceded they had underestimated the fire threat. Astronauts' photos showed that annual burning of forest and savanna in Africa and the Amazon basin has risen 10-fold since 1973. Humans torch about 5 percent of Earth's surface every year. Carbon dioxide and other gases generated are major contributors to greenhouse warming.

The realization that we simply do not know what we are doing to our planet has put the so-called ``Mission to Planet Earth'' at the top of the world's environmental science agenda. This is a set of national and international programs that combine space-based scrutiny with extensive surveys on land and sea. Over the next two decades, these should enable scientists to assess the state of the Earth.

Mission to Earth actually means several things at once. Nations working through the International Council of Scientific Unions know it as the International Geosphere/Biosphere Program whose goal is to understand the interrelation of the planet with its living community, from bacteria to people.

For the 60 scientists from some 14 countries who met in Bad Ischl, Austria, in February, it means 10 projects due in time for the 1992 International Space Year. They include, for example, a joint Brazilian and European Community effort to estimate deforestation rates and to map deforestation from 1983 to 1991. West Germany and the US National Aeronautics and Space Administration (NASA) will lead studies to learn what's happening to polar zones.

Canada and the United States are leading a project to make the most of available satellite data to produce a Global Change Encyclopedia of climate and atmospheric changes. Austria then will lead the work to translate the encyclopedia into a 300-page atlas to be ready by 1992.

For NASA, itself, Mission to Earth is a plan for satellite-based Earth observing that extends well into the next century. It starts with planned and existing satellites in the early 1990s and matures into several large polar-orbiting instrumented platforms - the Earth Observing System - to be launched starting in 1998.

This is a significant part of the Bush administration's Global Change Research Program. The program involves six agencies besides NASA and includes studies both from orbit and on the surface. According to presidential science advisor D. Allan Bromley, ``This approach has, as its central goal, the provision of a sound scientific basis for developing national and international policy on global change.''