What do extreme weather events tell us about climate change?

“Climate is what you expect. Weather is what you get.”

That famous quotation from science fiction great Robert A. Heinlein captures the difficulty climate scientists have when trying to share the science behind global warming to the general public through the media.

Thanks to a link shared by my friend and collaborator UGA Meteorology prof Marshall Shepard about a special issue of Earthzine that he edited, we can get a peek into the thinking of climate scientists who are striving to make those media communications work well.

In an article entitled “Changing the Media Discussion on Climate and Extreme Weather” By Christine Shearer and Richard B. Rood, the authors point out that under some circumstances, extreme weather events can indeed be linked to climate change.

In particular, two recent European heat waves cannot easily be dismissed as just weather, but should be recognized as strong supporting evidence of potentially dangerous global warming.

To quote the article:

Focusing on European heat waves, Barriopedro et al. [22] determine that the 2003 and 2010 European heat waves are the hottest of the past 510 years. That is, there have been two 500-year events in the past decade. These heat waves are determined to be more than four standard deviations from the 1970-1999 mean, extreme by any measure. Barriopedro et al. are confident in attributing more moderate heat waves (two to three standard deviations) to changes in a shift of a mean summer temperature, i.e. climate change. The more extreme events they link to enhanced variability, with such variability both consistent with the predictions from climate change models and becoming more likely in the next 40 years. Therefore, a definitive climate-change signal will emerge for these most extreme events.

Before commenting, I recommend that you read the complete article.

For a collection of book reviews on this subject, see the Science Shelf Book Review Archive weather and climate section.