Here it is in a nutshell: Bush denies the looming prospect of global warming because we can't afford to have people leave the coastal areas of the US.
Consider Miami. Many climatologists show maps of how southern Florida would be inundated by rising sea levels. If this news was taken seriously and publicized by our government, they would be obligated to do something about it. But what could you do for Miami? Isn't it already above sea level? Billions of dollars and many years would be required to build levees and other flood-control mechanisms, and it might already be too late. Residents of south Florida would move northward. Jeb Bush would have a crisis on his hands.
Consider New Orleans: the worst has already happened. Bush knew in advance that New Orleans was doomed (see the videos and news stories released today by AP) but didn't do anything about it. Why? There was nothing he could do to stop the flooding - the levees were not built strong enough to resist the storm and would break, the city would flood, and people would perish.
So my half-baked thesis boils down to this: Bush plans to let the shit hit the fan and worry about it later. He expects more catastrophes to occur, just like New Orleans.
Gotta go. The land yacht is thirsty again.