Stephan Lewandowsky Seminar - The "pause" in global warming in historical context: comparing models to observations?

Event type: 
15 August 2017
3.00 - 4.00pm

Climate Change Research Centre, Seminar Room, Mathews Building 4th floor, UNSW, Sydney

Stephan Lewandowsky
School of Experimental Psychology, University of Bristol, UK
Climate Change Research Centre, UNSW, Australia

The alleged significant slowdown in global warming during the first decade of the 21st century, and the appearance of a discrepancy between models and observations, have attracted considerable research attention. The slowdown has been variously labelled a “pause” or “hiatus”, and there has been much debate about whether or not the statistical evidence supports the notion of a pause or of a discrepancy between models and observations. In order to understand why researchers were drawn into this debate, it is crucial to consider the evidence as it was available at the time: Both model projections and global temperature data have been continually refined and debiased over time, with notable consequences on the evidence for a "pause". I show that in retrospect, using the best presently available data and model projections, there is no discernible evidence for a "pause" or a discrepancy between models and observations. However, depending on the data set and type of statistical analysis being used, evidence for a "pause" and a discrepancy between models and observations could be adduced at various times during the last 10-15 years.

Brief Biography: Stephan Lewandowsky is a cognitive scientist with an interest in computational modeling. Stephan tries to understand how the mind works by writing computer simulations of our memory and decision-making processes. Recently, he has become interested in how people update their memories if things they believe turn out to be false. He has become particularly interested in the variables that determine whether or not people accept scientific evidence, for example surrounding vaccinations or climate science.

Lewandowsky received his bachelor's degree from Washington College in 1980, followed by an M.A. in 1981 and a PhD in 1985, both from the University of Toronto. He is now a professor at the University of Bristol.