- He is talking about regional effects.
- He does not exclude anthropogenic warming from causes, and calls at the end for an examination of the links with greenhouse gas forcings.
As you can view above, Dr James Hurrell is a scientist at NCAR, Boulder, CO and has given evidence to Congress as recently as 2010 affirming the reality of anthropogenic causes of global warming stronger than natural causes alone.
There are 3 strands to weather/ climate.
- Random "Noise" Variation
- Natural Variability
- Anthropogenic Effects
The major findings of climate scientists in recent years is the swamping of natural effects by the long term trend of global warming due to greenhouse gases. Ironically, the major brake on that is another anthropogenic effect, the presence of sulphate aerosols, a form of pollution, which inhibits warming by reflecting the sun's rays.
That does not mean scientists are not studying natural variability, of which the role of the sun is of vital importance. Natural variability (ocean oscillations like the NAO, volcanic effects) and man-made warming/ cooling are not independent - for example, loss of sea ice reduces the earth's albedo, and as dark water will absorb more of the sun's energy that white ice, here the sun will add a positive feedback to global warming.
Here are some references from Skeptical Science:
David Archibald Exaggerates the Solar Influence on Future Climate Change