Climate change
is a change in the statistical distribution
of weather
patterns when that change lasts for an extended period of time
(i.e., decades to millions of
years). Climate change may refer to a change
in average weather conditions, or in the time variation of weather around
longer
-term average conditions (i.e., more or fewer
extreme
weather
events). Climate change is caused by factors such
as
biotic
processes, variations in
solar radiation
received by Earth,
plate
tectonics
, and
volcanic eruptions
. Certain human activities
have also been