Environmental Engineering Reference
In-Depth Information
Figure 1.9
Non-equilibrium conditions in physical
geography.
Source: After Renwick (1992).
of these elements are also linked through
climate and biogeochemical cycle coupling
,
acting as a major force in climate change and its consequences. Atmospheric temperature
varies with the quantities of atmospheric CO
2
(carbon dioxide), CH
4
(methane), H
2
O
(water vapour) and other chemicals, which create the
greenhouse effect
, leading to
changes in global ice cover and sea level. Thirdly, isotopes of the same elements
exchanged with the atmosphere and biosphere become trapped in glacial ice and ocean
sediments, creating a
palaeo
(
past
)
-environmental record
of previous states of Earth's
environments.
Geographers are familiar with the topical human impact of these environmental
changes, but less familiar with the processes and responses which drive them. The ability
to understand and explain, rather than merely describe, them is central to the relevance of
modern geography. It remains to be seen whether Earth System Science becomes an
enduring paradigm in its own right, or merely a sophisticated development of general
systems theory, but its significance for physical and human geography is undeniable. Its
purpose is to gather
proxy
and
documentary
evidence of past changes in the global
