An ecological view of water productivity

An interesting view from Jorg Imberger:

Human actions have a major impact on the future sustainability of our water resources. ...Some of the most important hydrological cycles (water, carbon, nutrients and heat) show how evolution has ensured a beautiful harmony between water and nature: water cycles through nature, sustaining it. In return, organisms of nature clean the water of harmful elements. Over the last 200 years, humans have impacted physically on these hydrological cycles, venting carbon dioxide into the atmosphere, denuding the surface of the earth of its natural vegetation and overloading water bodies with pollution.

Understanding Science: 13 Water- the next fifty years. (Link here). University of Cambridge, 2004.