Weather and climate

Climate
is the weather a certain place has over a long period of time. Climate has a
very important influence on plants, animals and humans and is different in
different parts of the world. Some scientists think that the world is becomming
hotter.

If you compare Moscow winter and
summer temperatures at the beginning of our century and at its end you will see
that climate has really changed. Winters have become warmer. Sometimes
there is little snow in January, and there were winters when it rained on the New
Year's Eve. Many people say that it is so because of the greenhouse effect.
During the last 100 years people have produced a lot of carbon dioxide.

This gas in the atmosphere works
like glass in a greenhouse. It lets heat get in, but it doesn't let much
heat get out. So the atmosphere becomes warmer. Where does the carbon dioxide
come from? People and animals breathe in oxygen, and breathe out carbon
dioxide. We produce carbon dioxide when we burn things. Trees take this gas
from the air, and produce oxygen. But in the last few years, people have cut
down and burn big areas of rainforest. This means there are fewer trees, and,
of course, more carbon dioxide!

As we see the climate in different
parts of the world changes a little from year to year. These changes can
be dangerous for our planet, which needs protection. Earth is millions of years
old, much older than the humans. We know many of its secrets. Yet there is
still much to learn.