Global climate change's effect on weather is both dangerous and complex. Some regions of the planet, like the Southwest and Central Plains of the United States, respond to rising global temperatures with extreme drought while other regions, like the Gulf Coast and Southeast Asia, become innundated with hurricanes and floods. These extreme weather events occur because the global climate system is out of balance and shifting, and when large-scale weather patterns shift, communnities must scramble to adapt.
Any way you measure it, from number of events to the cost of damages, 2011 was one of the most extreme years for weather disasters. In the United States alone, there were record numbers of tornadoes, blizzards, flooding, drought and wildfires. The National Oceanic and Atmospheric Administration has dubbed 2011 the "Year of Extreme Weather" and has committed to creating a weather-ready nation in 2012. You can read more about the disastrous events of last year and find out how you can help create a weather ready nation here: http://www.noaa.gov/extreme2011