Understanding science

13: Water - the next fifty years

Overview: The Science of Water

Jorg Imberger

Human actions have a major impact on the future sustainability of our water resources. Water transports and mixes the ingredients for life and removes the waste products. In this way water provides the medium in which life can flourish.

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 nature and in return the various organisms of nature clean the water of harmful elements. Over the last 200 years, humans have impacted physically on these hydrological cycles; venting the carbon dioxide back into the atmosphere, denuding the surface of the earth of natural vegetation and overloading water bodies with pollutants. This is resulting in catastrophic effects, raising the following important questions concerning current water resources planning:

1) Direct Effects: How will the release of greenhouse gases influence, in the long term, the atmospheric temperature, growth and melting of the ice caps, the depth of the oceans, the local precipitation, the frequency of droughts, floods and storms, the sequestering of carbon, the abundance of oceanic and terrestrial food resources and the surface runoff and groundwater recharge fractions?

2) Indirect Effect: Will biodiversity increasingly disappear as natural disasters impact on ever more partitioned natural reserves with an increased frequency?

Currently there are about two billion people who have inadequate access to drinking water and about three billion, or half of the world's population, who have inadequate sanitation. When these pressures are combined with the climate change/variability uncertainty we are likely to be confronted with rebuilding most of the world's infrastructure in the next 50 to 100 years. The costs will be enormous, adding urgency to the need to understand the underlying science and so be able to manage the risk.

Prof Jorg Imberger is Professor of Environmental Engineering and Chair of the Centre for Water Research, University of Western Australia

The title of this document is: Understanding science: 13: Water - the next fifty years
URL: http://www.cam.ac.uk/about/scienceseminars/water/overview.html

Seminar presented: 08/10/2004