The Earth has gone through many cycles of warming and cooling
in the past. As Earth's climate changes, nature responds to
bring things back into balance.
We know there has been an increase of carbon dioxide in the
atmosphere during the last 100 years. We also know that carbon
dioxide absorbs heat from the Earth's surface, slowing the
escape of heat from the Earth's surface to space. This is
the Greenhouse Effect. This increase in carbon dioxide
(CO2) has been partially linked to human activities,
such as manufacturing and burning large areas of forest.
Some scientists think this will cause the Earth's ice caps
to begin to melt, causing ocean levels to rise. Coastal cities
would risk flooding. Other scientists think the Earth will
adapt. One thought is that some plants will benefit from more
carbon dioxide. Since plants use carbon dioxide, this may
make them more efficient growers. Some evidence of this may
already be occurring in some types of ocean algae. When the
algae die, it sinks to the ocean floor, taking carbon with
it. This is called carbon sequestration, and is a way
the amount of carbon dioxide in the atmosphere might be reduced.
Another adaptation that may happen is a change in the Earth's
cloud cover. A warmer climate may increase water evaporation.
More water vapor in the atmosphere could increase cloud cover.
Sunlight would be directly reflected out into space before
it reaches the Earth's surface, making less available to heat
If these adaptations occur, a change in Earth's climate would
still take place, but the change may not be as drastic as
some predict. It usually takes decades or centuries for changes
in climate to take place. We will not know the total effect
of the warming atmosphere on Earth's climate and ecosystems
for some time.
This does not mean that attempts should not be made to reduce
the amount of carbon dioxide people are putting into the air.
Recently, many governments worldwide met to set up limitations
on the amount of carbon dioxide and other greenhouse gases
(gases that slow down heat escaping from the Earth). Individuals
can do their part by doing things like planting trees and
using products that do not release large amounts of carbon
dioxide into the atmosphere.