Global warming is happening now and its effects are being felt in the United States and around the world. Among the expected consequences of global warming is an increase in the heaviest rain and snow storms, fueled by increased evaporation and the ability of a warmer atmosphere to hold more moisture.
Extreme downpours are now happening 25 percent more often in Colorado and 30 percent more often nationwide than in 1948. In other words, large rain or snowstorms that happened once every 12 months, on average, in the middle of the 20th century now happen every nine to ten months in Colorado and across the country.