A friend of mine from the Physics dept. at Lehigh University passed along a pointer to a recent paper published in Physical Review Letters (one of the most prestigious and well refereed publications in Physics – and the only place I ever managed to publish, so ya know it’s good.)
Here’s the abstract:
“The solar influence on global climate is nonstationary. Processes such as the Schwabe and Gleissberg cycles of the Sun, or the many intrinsic atmospheric oscillation modes, yield a complex pattern of interaction with multiple time scales. In addition, emissions of greenhouse gases, aerosols, or volcanic dust perturb the dynamics of this coupled system to different and still uncertain extents. Here we show, using two independent driving force reconstruction techniques, that the combined effect of greenhouse gases and aerosol emissions has been the main external driver of global climate during the past decades.”
In other words, having analyzed the temporal spectrum and the pertubative forces in two different ways, the authors are able to point to a human origin for the present round of global warming. The fact that both methods show the effect is a strong indication that this isn’t just a model dependent artifact.
This’s actually good news. It means if we modify our behavior we can slow down or even stop it. The idea that the present global climate change was completely natural would mean that it would be a much more difficult phenomenon to deal with – especially if it was more solar based than terrestial.