The answer to this question explains why we are interested in “event” or “extreme” forcing. The climate of the Chesapeake Bay region is made up of lots and lots of days of weather. Those weather days may be cold or warm, or dry or wet, but together on average they produce our climate. Strangely enough, it’s quite possible that we never actually experience a day that is exactly like our climate, because day to day weather is usually more extreme than the average of all the weather days.
So what does this mean? It means that we could have some very cold weather even as the climate warms. The map on the right from NOAA’s National Climate Data Center says it all. Earth just had its warmest winter on record. But in the American east, weather patterns created cold conditions.
If we look even closer, we see that a number of cold spells in February were responsible for the cold winter in this region, but overall earth warmed.
So what does this mean for people living around the Chesapeake Bay? Although we learn a lot from looking at climate (such as understanding how the average of all the days of weather is changing), we don’t feel climate, we experience weather. So even if we know our climate is warming, we need to understand how often cold events will occur to plan for emergency homeless shelters, whether we need double paned windows, or how much wood to lay up for the winter. We want to know whether cold weather will stop altogether, or whether it may just be less frequent. After all, it doesn’t matter if we get a cold spell every 10 years instead of every 5, we still will need a good furnace and snow plows when an arctic blast blows through!
The same considerations affect the plants and animals around us. If the climate warms, then maybe fish and plants that live south of us will move into the Chesapeake as native organisms adapted to our old colder climate head north. But if we still get occasional cold snaps, the warm climate adapted species may not survive. It may depend on how often cold spells occur, and how resilient the new species are to a cold snap (how quickly they rebound from a disturbance).
In our NERR project, we are looking beyond how the average climate is changing, to try to understand how the weather or intense weather events are changing. By learning more about these events, and how the CBNERR’s are affected by major weather disturbances, we hope to be able to better understand how they will respond to future climate changes.
Thanks to Dan Satterfield’s blog for highlighting these figures.