Human influence on the global environment has increased considerably this century. In the early 1900s there were severe local environmental problems, mainly in densely populated areas, but the influence on the global environment was hardly noticeable. The situation at the end of the century has changed drastically. Anthropogenic influences on the overall composition of the atmosphere are already partly dominating natural processes. The stratospheric ozone destruction by CFCs and other artificial chemical constituents and the climate warming caused by increased greenhouse gas emission are problems that are now facing humankind. It is to be expected that the environmental problems will be more severe in the future because of the increased population and the likelihood that advanced industrialization will encompass the whole world.

Environmental problems are by their nature complex, because they often include series of intricate feedback processes. They cannot therefore be predicted exactly, and major surprises in the way the environment will respond to anthropogenic and other influences must be expected. An area that requires much more scientific attention is the interaction between the biosphere, the geosphere, and the climate. That such major interactions occur is well documented from palaeorecords, which show that the past climate of the Earth was very different from what it is today.

To address these issues a Study Conference on “Geosphere-Biosphere Interactions and Climate” was organized by the Pontifical Academy of Sciences 9-13 November 1998 at the headquarters of the Academy in Vatican City.