In this ninth part of our mini-series on climate science, we turn to one of the key suspects in extreme weather events we have experienced in recent years—the shifting shape of the North Atlantic jet stream. And the fingerprints of the changing jet stream can be found in tree ring data. The guest in this episode has studied three centuries of European tree rings and found that the shape of the jet stream, along with clear deviations from historical weather, began in the 1960s, pointing to a connection to the changing climate. Other researchers have come to similar conclusions by studying things like the difference between Arctic and mid-latitude temperatures over time. And they conclude that increases in greenhouse gas emissions will make the jet stream increasingly wavy in the future, exacerbating such extreme weather events.

Geek rating: 3

Guest: Valerie Trouet received her PhD in Bioscience Engineering at the KULeuven (Belgium) in 2004. After a post-doctoral research position in the Geography Department at the Pennsylvania State University (2005-2006), she worked as a research scientist at the Swiss Federal Research Institute WSL (2007-2010).  She now is an Associate Professor at the Laboratory of Tree-Ring Research at the University of Arizona and leads the Spatiotemporal Interactions between Climate and Ecosystems research group.  She is currently writing a broad audience book about tree rings, climate history, and human history under the working title “Treestory.”

On Twitter: @epispheric

On the Web:  Trouet Lab

Recording date: February 20, 2018

Air date: March 21, 2018


Teaser photo credit: By The original uploader was Ellywa at Dutch Wikipedia – Transferred from nl.wikipedia to Commons by Koektrommel using CommonsHelper., Public Domain,