No Increase in Extreme Weather

Philip Angell of the World Resources Institute had a letter published in the New York Times this week blaming recent floods and droughts on global warming. He talks about a “new normal” of extreme weather events. Yet floods and droughts have occurred throughout the earth’s history, and likely always will. So what evidence do we have to support the frequently made assertion that global warming is causing alarming precipitation extremes?

The National Oceanic and Atmospheric Administration (NOAA) tracks the frequency of floods and droughts. According to NOAA there has been no upward trend in extreme precipitation events (floods plus droughts) during the 20th century. Indeed, if there is any trend at all, it is a trend of less frequent floods and droughts. Not a single year in the past decade cracked NOAA’s Top 15 list for extreme precipitation events, and each of the top six years occurred prior to 1985.

Today’s media can certainly bring any drought, flood, or other noteworthy weather event directly into our homes, but that doesn’t mean that more such events are occurring lately or that global warming is to blame.