Environmental Engineering Reference
In-Depth Information
which are being looked at to see whether chaos theory is applicable include tropical
storms, earthquakes, volcanic eruptions, convection cells driving plate tectonics, glaciers
and Ice Ages, mass movements, and periglacial patterned ground.
THE RISE OF EARTH SYSTEM SCIENCE
The twenty-first century brings with it further developments of the systems approach,
driven by awareness of rapid climate change and international concern for its impacts on
global physical environments and human activities. The study of global geochemical
cycles by Bolin, Lovelock and others integrated large parts of the newly emergent
environmental sciences during the 1970s and 1980s. Focusing on environmental
chemistry and physics, rather than geographically based studies of climate,
geomorphology and biogeography, it reinforced rather than revolutionized the general
systems paradigm. However, by 1990 NASA's developing space shuttle programme of
Earth - atmosphere investigations, the recovery of intriguing environmental data by
drilling through deep ocean sediments and ice sheets, and measurable shifts in climate
and sea level, galvanized the international scientific and political communities.
For the first time it became apparent that human activity might be forcing global
environmental changes, particularly through fossil fuel combustion and other industrial
and agricultural interventions in the very biogeochemical cycles on which humans and
climate depend. This has led to the modified paradigm of
coupled systems
and the new
integrative discipline of Earth System Science, as well as the formation of transnational
organizations such as the Intergovernmental Panel on Climate Change to develop a global
response across all fields of public policy. Earth System Science draws physical
geographers, geologists and environmental scientists into close interdisciplinary research,
currently focusing on three key aspects of global environmental change.
First, compounds and isotopes of the 'structural' elements which form living biomass
(carbon C, hydrogen H and oxygen O) together with those of nitrogen N, sulphur S and
other elements, are all inextricably linked with the hydrological cycle, plate tectonic
activity, rock formation and weathering. These so-called
acid-base, oxidation-reduction
balances
are therefore implicated in environmental problems associated with acid rain,
water balance, ozone depletion and other global concerns. Secondly, most
