Actually a nuke would probally set off a underground oil fire that would cause a chain reaction involveing the conecting oil reserves, thus makeing the woulds largest ever BBQ, and destroying the atmosphere to the point that greenpeace would finally be right about something.
Not to mention that the price of gas, oil, heating fuel , ..etc... would be so high that no one could afford it anymore, and without haveing a workable electric car yet that recharges itself on solar power ( that wouldn't be there any more because of the dark cloud covering the planet ) we'd all be rideing horses until everything on the planet died from a lack of sunlight, or the acid rain, or maybe even the next ice age.
I highly suggest we never find out.
