1. Potentially adverse climatic change resulting from human activities
2. Potentially adverse changes in biota and man from contamination by
toxic substancesincludingradionuclides
3. Potentially adversechangesin biological productivity causedby improper
land use (reduced soil fertility, soil erosion, extension of arid zones etc.)
A second category includesproblemsthat, although of great importance,
are not suitable for early globalmonitoring either because of their nature or
because further study is necessary to determine whether they should be
included in a global environmental monitoring system. These problems are:
4. Potentially adverse changesin the growth, structure and distribution of
the human population
5. Changesin the subjectivehuman perception of the environment
6. Eutrophication of waters
7. Decreasingfreshwaterresources
8. Natural disasters