Weather and Climate

There has been a lot of commentary on TV and the blogosphere lately about the recent cold snap in certain regions of the northern hemisphere, particularly in the southeastern United States. While this cold snap is very bad for some citrus and produce growers, events like this are not unusual during the winter and are not an indication of any global cooling trend. I have written before on the difference between weather and climate, and how you need to look at weather records of at least thirty years to see any kind of overall climate trend.

This does nothing to stop the defenders of the status quo from getting all worked up about how wrong all those climate scientists are. Meanwhile in the southern hemisphere Australia is suffering from heat waves and massive crop losses.

The changes that are happening to the global climate system will cause more extremes of both hot and cold, because adding more energy to the system will cause more disruptions in the normal jet stream patterns. This will allow cold air to flow down from the poles as well as warm air to move north. While the freeze in the southeast is grabbing all the headlines the west coast has been warming, and the Vancouver Olympic organizers may be starting to get nervous.

I will close this post with a graphic representation of record heat versus record cold since the 1950's from Dr. Joseph Romm's excellent blog Climate Progress: This is only for the U.S., but the change in ratio is striking.

I will bet that there are more record highs set in the U.S. in 2010 than record lows - anyone want to take me up on it?