One of the most visible consequences of a warming world is an increase in the intensity and frequency of extreme weather events; weather is now a major news subject. Data over the last few years has shown that the number of heat waves, heavy downpours leading to flooding, droughts, and major hurricanes has increased worldwide and the strength of these events has increased as well. Increases in heavy precipitation may not always lead to an increase in total precipitation averaged over a season or over the year, but will increase flooding hazards since the rainfall occurs over a short time period.

The connection between global warming and these events is not straightforward since each event can not be directly tied to climate change, but the likelihood of these events occurring is increasing due to climate change. The impact of climate change on precipitation is further complicated due to the fact that dry regions are expected to become drier and wet regions are expected to become wetter.