Environmental Engineering Reference
In-Depth Information
increase seems quite small when compared to the regular occurrence of
daily temperature variations of 10 to 20 degrees that everyone experi-
ences, but the number of observed changes in the inorganic world and
the migrations of plants and animals noted earlier testify to the exquisite
sensitivity of both the organic and inorganic world to even small changes
in average yearly temperature. And the ecological changes are not only
in the range of mobile species. There is evidence that the genetic makeup
of species such as fruit fl ies and birds is changing to adapt to the warmer
temperatures.
1
The fact that a change in average temperature by less than
1 degree in a century, one-hundredth of 1 degree per year, can change
so many biologically controlled things on the earth's surface is hard to
believe. But it cannot be denied.
The scientifi c consensus is that the world can probably expect centu-
ries of gradually increasing temperatures and attendant disrupting effects.
Even if humans stop burning coal and oil tomorrow, we have already
spewed enough greenhouse gases into the atmosphere to cause tempera-
tures to warm and sea levels to rise for at least another century. This
results from thermal inertia. Even if no more greenhouse gases are added
to the atmosphere, an impossibility in the world's existing fossil fuel-
based economies, global air surface temperatures will rise about another
1ºF and global sea levels will rise at least 4.3 inches by 2100.
2
As we
continue to pump greenhouse gases into the atmosphere, the undesirable
effects get worse—probably several degrees more of temperature increase
and many more inches (perhaps feet) of sea level rise. Our ability to
minimize these effects depends on how fast action is taken by people and
their governments, but the longer we wait before implementing changes
in our energy use and food consumption patterns, the smaller the effect
we can have on them in this century.
Who's Going to Suffer?
What do we have to look forward to as the temperature climbs?
We can expect current trends to continue and probably accelerate—
continuing migrations of plants, animals, and perhaps humans; spread-
ing of malaria and other heat-dependant diseases; more frequent and
severe heat waves; increased average rainfall occurring in heavier down-
pours; increased river fl ooding; water stress in lowland areas that depend
on winter mountain snowpack for summer moisture; more severe hur-
ricanes and storm surges; loss of most of the world's glaciers; rapidly
rising sea level; increased coastal erosion; some acidifi cation of the
