This is a very broad question and a topic about which entire books have been written, films made, and institutes established. Here is a basic outline reflecting climate patterns and change:
1880- Surface temperatures are measured
1979 - Satellites measure atmospheric temperatures up to 30,000 ft
1980 - Climate temperature has increased by 1.0 degree
1980 - 1995 - Eleven years of the warmest temperatures measured since record keeping began
Patterns of climate change in the form of global warming are affecting "the global water cycle: the exchange of water among the oceans, atmosphere, and land." Increased evaporation leads to drier soil; more water in the atmosphere, however, means more rain and snow.
In the U.S., precipitation has gone up 6% since 2000. This extra water causes floods, leading to soil erosion. In other parts of the country, evaporation is leading to severe drought.