That's funny - this is exactly what the professional Chicken Littles were hollering about in the early '70s...
That was the fad then. It didn't work on schedule so they went from nuclear winter to global warming. Now that global warming is begining to wan enviro-whacos have to build another altar. Meantime we just ignore these nuts and keep on keeping on. Mother nature will give us plenty of time to adjust to any changing conditions.
In the 70s, the slight cooling was related to high quantities of atmospheric SO2 primarily from coal burning. This is a different mechanism (and I'd still like to know why he thinks this is going to happen).