Since many years attention of most international organizations, like UN and UNESCO is focused on Sustainable Development. It is beyond doubt that economical development of western world and of other rich countries by no means has been until now sustainable; it has had a great responsibility in overexploiting natural resources, in increasing environmental pollution and, according to scientists' opinion, in influencing a global climate change. In September 2002 in Johannesburg at the World Summit on Sustainable Development international community recognized that sustainable development should be based on equity in sharing natural resources and on cooperation, at various level, in managing them.UN and UNESCO have declared the present year 2003 the "Water year" to claim attention, at local, regional and international level, towards serious problems: even if water is abundant, covering about 3/4 of earth surface, we observe a decreasing availability of drinkable water and an increasing pollution of ground, surface and sea waters. Furthermore we hypothesize that human activities play a relevant role in perturbing thermal and mass exchange between oceans and atmosphere; that perturbation is suspected to influence micro/macro-climate change responsible of: droughts, floods, desertification, glaciers melting etc.Change in the range of climate variation and extreme events have a great impacton socio- economic sectors (e.g. agriculture, viniculture). Summarizing, we remark that on one side thermal and mass exchange between water and atmosphere influences climate, on the other side climate change has a profound impact on the components of the water cycle, including catchment and its management. Environment is a complex system: any action on its elements causes a feedback, whose size cannot be exactly foreseen. If perturbations are not too large or too frequent, environmental parameters are allowed to oscillate close to those corresponding to a dynamic equilibrium state; on the contrary, oscillations might get the system out of its equilibrium; in that case it cannot be restored. Nobody is able to foresee consequences on the complex system of living beings.Governments are becoming aware that most environmental disasters, affecting also our daily life, raise from human actions and joint negligence both at social and individual level. Coercive measures taken by governments may stimulate negative reactions, while environmental regulations may be effective if citizens become sensitive towards environment, have opportunity to develop knowledge, critical thinking and are involved in a highly participative democracy.Education is a crucial knot in that process. Through a sound knowledge of processes regulating ecosystems, students, teachers, citizens could grow their awareness and attitude to modify behaviour and policies needed to really achieve sustainable development.