Global Warming
Increases in the
numbers of cattle and rice fields have increased the amount of methane released
into the atmosphere.
Carbon dioxide and methane in the atmosphere absorb most of the energy radiated
by the Earth. Some of this energy is reradiated back to the Earth and so keeps
the Earth warmer than it would otherwise be.
Increasing levels of these gases may be causing global warming by increasing the
‘greenhouse effect’. An increase in the Earth’s temperature of only a few
degrees Celsius:
− may cause quite big changes in the Earth’s climate
− may cause a rise in sea level.