| It is important that
we understand the climatic system, especially in the face of possible global
warming. Most scientists agree that it is a possibility that global warming
is occurring. However, the rate and amount of expected change are not entirely
clear. There have been other warm periods in the Earth's history. We are
now in an interglacial, or warm period, that began when the last Ice Age
ended, about 10,000 years ago. Scientists know that many changes in climate
have been, and can be, caused by natural forces.
Scientists need to know how much of the Earth's present warming is due
to natural factors and how much is due to human activity. They also need
to know at what rate climatic changes are happening. By knowing how much
human and natural factors influence climate, scientists can suggest a
plan of action to postpone global warming or help people adapt to it.
Just as the Earth's climate
changes, the earth's surface changes too, as this slide shows. The earth's
surface is constantly shaped and reshaped by incredibly powerful processes
such as earthquakes. This 5-meter high colony of coral (Pavona clavus)
is from the Galapagos Islands off the coast of Ecuador in the Pacific
Ocean. This reef, once underwater, was lifted high and dry during a turbulent
period of earthquake activity in 1954. Examples such as this terrestrial
reef are evidence that our planet is always changing. Most of these environmental
changes however, are less dramatic than the rise of the ocean floor or
the eruption of a volcano. One less dramatic change that we are able to
investigate is the rate at which coral grows. By examining the growth
rate of coral, scientists are able to determine what the climate was like
when the coral was submerged and alive in the ocean.
Department of Biology, University of Houston
Click on above image to enlarge.
Download a zip file
of a full resolution TIF image