Causal role of antecedent sea-surface temperature in European summer temperatures

Determine whether a physical causal pathway links Northern Hemisphere spring sea-surface temperature to Northern Hemisphere summer temperatures in central Europe, or whether the observed association is purely statistical.

Background

The paper uses conditional attribution to examine how conditioning on atmospheric blocking, antecedent precipitation, and spring sea-surface temperature changes attribution results for the European summers of 2006 and 2007. The statistical model can represent associations between these conditioning variables and summer temperature, but it does not by itself establish the direction or existence of causal relationships.

The authors specifically note that the attribution results involving spring sea-surface temperature cannot establish whether that variable mediates the effect of climate change on central European summer temperatures. They explain that controlled experiments, potentially implemented in weather or climate models by prescribing or constraining the conditioning variable, would be needed to distinguish a genuine causal pathway from a purely statistical association.

References

Based on our results in Sect.~\ref{sec:res} alone, we cannot determine whether there is a physical pathway linking NH spring sst to NH summer temperatures, or whether the link is purely statistical.

— On the role of moderator and mediator variables in conditional event attribution of heatwaves over Europe  (2609.08507 - Buschow et al., 8 Sep 2026) in Section 6, subsection “Correlation vs Causation” (\label{sub:corvscaus})