Comparing variability and trends in observed and modelled global-mean surface temperature
Article first published online: 19 AUG 2010
Copyright 2010 by the American Geophysical Union.
Geophysical Research Letters
Volume 37, Issue 16, August 2010
How to Cite
2010), Comparing variability and trends in observed and modelled global-mean surface temperature, Geophys. Res. Lett., 37, L16802, doi:10.1029/2010GL044255., , and (
- Issue published online: 19 AUG 2010
- Article first published online: 19 AUG 2010
- Manuscript Accepted: 6 JUL 2010
- Manuscript Revised: 1 JUL 2010
- Manuscript Received: 8 JUN 2010
- climate variability;
- climate trends;
- climate models
 The observed evolution of the global-mean surface temperature over the twentieth century reflects the combined influences of natural variations and anthropogenic forcing, and it is a primary goal of climate models to represent both. In this study we isolate, compare, and remove the following natural signals in observations and in climate models: dynamically induced atmospheric variability, the El Niño-Southern Oscillation, and explosive volcanic eruptions. We make clear the significant model-to-model variability in estimates of the variance in global-mean temperature associated with these natural signals, especially associated with the El Niño-Southern Oscillation and explosive volcanic eruptions. When these natural signals are removed from time series of global-mean temperature, the statistical uncertainty in linear trends from 1950 to 2000 drops on average by about half. Hence, the results make much clearer than before where some model estimates of global warming significantly deviate from observations and where others do not.