Environmental Engineering Reference
In-Depth Information
coming solar radiation. Like the elk, the surrounding rocks and trees absorb
solar radiation and reradiate that energy back to the environment, some of
which is absorbed by the elk. The
elk's own metabolism will produce
heat much like a furnace in a house.
The elk must balance the exchanges
of heat energy with the environment
in order to prevent overheating or
freezing. That is, the elk reaches its
own steady state body temperature by
balancing absorbed and emitted radi-
ation.The elk does this through be-
havioral and physiological means that
are determined by its phenotype.
Thus, the physiological and behav-
ioral traits that make up its phenotype
determine the range of environmental
conditions that it can tolerate, as illustrated with the rabbit example above.
The climate-space approach allows us to formalize these physical processes
and quantitatively account for the effects of the thermal environment on an
organism's energy (heat) budget.The climate space effectively represents the
outer boundary of a fitness “contour map.”The power of a climate-space ap-
proach is that it can be extended to understand and forecast the effects of cli-
mate change on a species' geographic range, as is demonstrated in Box 3.1.
The climate-space approach allows
us to formalize these physical
processes and quantitatively ac-
count for the effects of the thermal
environment on an organism's en-
ergy (heat) budget. The climate
space effectively represents the
outer boundary of a fitness “con-
tour map.” The power of a climate-
space approach is that it can be
extended to understand and fore-
cast the effects of climate change
on a species' geographic range.
Effects of Global Climate Change
We now are entering an era where global climate change, brought about by
rising levels of greenhouse gases, has the potential to alter the distribution
of life on the planet as we know it. It is easy to deduce using the principles
described at the beginning of this
chapter that higher atmospheric con-
centrations of greenhouse gases will
lead to rising average global temper-
ature. But, what exactly is that new
temperature? What will be the atten-
dant consequences of that tempera-
ture rise on the diversity of life on
earth?
We now are entering an era where
global climate change, brought
about by rising levels of green-
house gases, has the potential to
alter the distribution of life on the
planet as we know it.
