[QUOTE="Pip"] Now there's a thing. I read just the other day of a "newly realised" factor affecting global warming ... soot. Particularly, particulate emissions from industrial sources and diesel engines (I always knew that diesels were the work of the devil, see) which are coating and becoming embedded in Polar ice, reducing the reflectivity and adding therefore to global warming. Pretty fucking obviously, dirty blackened ice doesn't reflect sunlight nearly as well as pristine white ice. QED.[/QUOTE] All of which pales to insignificance against one decent volcanic eruption. IMHO HS has very little effect on the weather. We do rather well on desertification though which should be the priority.