Geoscience Reference
In-Depth Information
Figure 1.4
A schematic
diagram of the physical and
physiological processes
represented in the second
generation Simple Biosphere
(SiB2) soil vegetation
atmosphere transfer scheme.
(From Colello
et al
., 1998,
published with permission.)
See Plate 2 for a colour
version of this image.
expanded. With the start of the industrial revolution in the late eighteenth century,
humans developed the ability to harness power from fossil fuels and transitioned
from mostly observers to participants in global change. We have significantly
altered the biogeochemical cycles of carbon, nitrogen, sulfur, and phosphorus.
Alteration of the carbon cycle has changed the acidity of the oceans and is chang-
ing the climate of Earth. Chemical inventions such as chlorinated fluorocarbons
(CFCs) have altered the ozone in the stratosphere and the amount of ultraviolet
light reaching the Earth's surface. The footprint of our chemical activities is now
found in the air, water, land, and biota of Earth in the form of naturally occurring
and human-created molecules.
The anthroposphere has expanded to occupy land for dwellings and agriculture.
Human dwellings now occupy about 8% of ice-free land and about three-quarters
of the land surface has been altered by humans in some way. As mentioned above
and discussed in more detail in later chapters, changing the nature of the land
