Geography Reference
In-Depth Information
of the Earth's system. It allows us to understand what resources we
have and how they are affected by different processes occurring on
different parts of the planet.
The environment is dynamic and we know from the material
covered in this topic that complex feedback mechanisms operate
on Earth that sometimes throw up surprising rates and directions of
change. A gradual slow change, which allows lots of time to think
about a management solution, may suddenly become a rapid
change if the system has reached a threshold and it suddenly jumps
out of one stable state. This is a bit like a deltaic river that suddenly
shifts its course due to a slow gradual build up of sediment clogging
the channel which no longer provides an optimum route for flow.
For another example in the Earth's system, look at the discussion
on the thermohaline circulation system in Chapter 2. These exam-
ples tell us that the physical environment and environmental
change is often uncertain. However, management action is needed
early, probably well before there is a clear understanding of how
things are going to change. This is known as the
precautionary
principle
. There is risk involved in taking early action because it
might physically be the wrong action and it may also be costly to
implement and may not have been required. However, often the
costs and physical consequences of not taking early action are
enormous. The discussion on the economic impacts of climate
change outlined by Sir Nicholas Stern as discussed towards the end
of Chapter 2 is a good example.
Fossil fuel is the main energy source that we use today. Devel-
oping nations which account for most of the world's population
are increasing fossil fuel use and this is likely to continue as they
develop, even if the rich nations stabilise or reduce their emissions.
Nuclear power carries safety concerns and is expensive but is a way
to reduce greenhouse gas emissions. However, there are other ways
forward. Nations have been meeting to discuss international agree-
ments on emissions. Many countries are setting targets to reduce
carbon use in energy provision. New energy sources are being
sought and technology improved to harness wind, wave, biochem-
ical and solar energy. Care is needed though to fully think through
the impacts of what appear to be low carbon resources. The palm
oil biofuel example discussed in Chapter 2 is a case that should
raise concern. More broadly, taking up land for biofuels or other
