So Where Is Global Warming Now?

It’s cold here in Oklahoma, though not as cold as in many other parts of the country. Of course this would be the day on which I began teaching my general bio class about global warming. Could I have chosen a worse time?

Actually, it was a good time to teach about this subject. Yesterday (Sunday January 26) it was quite balmy, in the 70s F. Overnight the temperature dropped 40 degrees F. So the weather of these last two days perfectly illustrated my point that weather is not climate. You can’t just stick your head out the window and tell whether global warming is occurring or not. You need long-term and large-scale temperature data, which is what the IPCC has accumulated and continues to accumulate.

So where is global warming now? I told my students that this is a good question, one that critical thinkers should be asking, but I have two answers. First, it’s somewhere else at the moment. Down in Australia, where they are having a big tennis competition, some of the tennis shoes of the participants started to melt on the court. Australia is having a record heat wave. Second, it’ll be back. Oklahoma had record heat waves in 2011 and 2012, but not 2013. But the high temperatures will be back. With global climate as well as local weather, the temperatures go up and down and up and down…but they go up more than they go down, and they go up more often than they go down.

Also, I showed the students some of my data regarding tree budburst times in southern Oklahoma. During the period of 2008-2012, the buds of some tree species opened between 2 and 3 days earlier each year. This period is not necessarily typical of all recent time periods, but it really did happen. I have data from lots of trees of numerous species. The advantage of using budburst times is that the plants integrate the weather conditions. They open their buds in response to the overall effect of warm and cold days in the winter, and also in response to lots of other factors, such as drought damage or disease that may have affected them the previous summer. Four hundred budburst data can integrate the effects of thousands of meteorological data for any given year.

So the “polar vortex” created a teachable moment for me today.

This essay also appeared on the blog of the Oklahoma Academy of Sciences.