posted on Feb, 13 2007 @ 03:44 PM
I believe the theory goes that all the thrown up ash and dust results in a layer that deflects the sun's light and cools down the planet. This is
where the term Nuclear winter comes from, and the similar Volcanic winter and (I think) Cosmic winter (after a meteorite/comet strike).
I can more easily explain it with volcanic winter, there are more examples of it (thankfully). The ash is blasted into the stratosphere, creating a
blanket of material that reflects the sun's light, preventing heating and cooling down the planet. For an example, after Tambora's eruption and
that of Krakatoa, which caused global cooling, and the Year without a Summer
both of these were quite short lived effects, and would probably only slow down global warming.
Worldwide nuking would probably be longer lasting cooling effects, but I think I prefer heat or moving further north to slow painful death from