In 1999 the International Centre for Mechanical Sciences celebrates thirty years of activity. For this celebration CISM has organized a series of courses and meetings on environmental problems, one of the leading subjects today of theoretical and applied research all over the world. The results obtained directly influence our daily life, particularly in applications for protection from pollution and natural hazards. The most significant of the events was the Conference on "Environmental Applications of Mechanics and Computer Science , where prominent scientists in the field present significant examples of the scientific approach to large scale phenomena involved in environmental problems.