Global climate models violate scaling of the observed atmospheric variability

TL;DR

This study evaluates seven global climate models using detrended fluctuation analysis and finds they fail to replicate the universal scaling behavior of observed temperature records, with notable differences between scenarios.

Contribution

It provides a systematic assessment of climate model scaling performance using a novel analytical approach across multiple sites and scenarios.

Findings

Models do not reproduce observed scaling behavior.

Performance varies significantly among models.

Overestimation of trends in greenhouse gas only scenario.

Abstract

We test the scaling performance of seven leading global climate models by using detrended fluctuation analysis. We analyse temperature records of six representative sites around the globe simulated by the models, for two different scenarios: (i) with greenhouse gas forcing only and (ii) with greenhouse gas plus aerosol forcing. We find that the simulated records for both scenarios fail to reproduce the universal scaling behavior of the observed records, and display wide performance differences. The deviations from the scaling behavior are more pronounced in the first scenario, where also the trends are clearly overestimated.