The future of the world is drought and hurricanes and eventually mass starvations in the developing world and wars over water. The long term impact on our economy and way of life is probably beyond measure.
But it will be the Great Unmentionable during the 2012 presidential campaign. If Obama mentions it, it will be in the context of "Green Jobs". If Romney mentions it, it will be to denigrate scientists and pointy headed intellectuals as a cheap throw-away to his mouth breathing base.
It will be climate change, not the deficit that will make us medieval Rome.