Vortrag im Rahmen des University of Vienna Physics Colloquiums
Climate science is highly visible in the public sphere, as its findings imply a clear call for action on anthropogenic climate change. At the same time, the field faces increasing scrutiny. While earlier challenges often involved outright denial, contemporary critiques more frequently rely on deflection, delay, and the amplification of uncertainty, portraying climate science as unusually uncertain compared to other disciplines.
This lecture examines what causal links climate scientists can legitimately make, how these links are established, and how uncertainty shapes—but does not preclude—robust conclusions. Drawing on more than a decade of experience from World Weather Attribution (WWA), it uses event attribution studies as a central example of scientific causal reasoning. Event attribution assesses whether and to what extent human-induced climate change has altered the likelihood or severity of specific extreme weather events. Such studies have become routine, with heatwaves dominating in Europe and globally and heavy rainfall studies concentrated in parts of Asia and North America, while major gaps remain, particularly for small island states.
The lecture highlights recent findings showing that for temperature extremes, differences between datasets often explain more variance than the precise definition of an event. This has implications for the added value of further quantitative attribution in well-studied regions and for identifying when new analyses are scientifically necessary. Crucially, the lecture distinguishes between quantitative causal statements (e.g. changes in probability or intensity) and qualitative causal conclusions (e.g. whether climate change made an event more likely or severe). It shows that even where data are sparse or models are limited, strong qualitative causal links can often be established by synthesising multiple lines of evidence, including physical understanding, observations, and model result.
A light lunch buffet will be offered before the lecture at around 13:00.
