examines the atmosphere as a system, and several atmospheric phenomena
that have become critical in the understanding and guardianship of our
environment. The current state of the atmosphere is the result of a multitude
of facts. The energy from the sun produces the movements or currents in
the atmosphere. This energy, the Earth's movement relative to the sun,
and the components of the atmosphere and of the Earth's surface maintain
the long-term climate, the short-term weather, and the temperature conditions.
These provide conditions fit for the forms of life found on Earth. The
condition of the physical world affects and is affected by the life present.
The entire system is therefore called the biogeochemical system. In the
last century especially, this system--which evolved over billions of years--has
been subject to rapid changes due to industrial activities increasing
at unprecedented rates.
This unit discusses some of the basic science and details of the interactions
involving the atmosphere. We begin by examining the nature of the sun's
energy, and the actions and reactions it produces in the atmosphere. We
then discuss how industrial activity has perturbed atmospheric conditions,
and what policy actions are being taken to reduce our impact. Due the
complexity of the atmospheric system, there are still large amounts of
scientific uncertainty in predicting changes precisely, but we do know
enough to describe and project qualitative features of the system that
lead to an understanding of the impacts of large scale human activity.