Using your logic:
There's been massive flooding in the UK in recent weeks. So if the government allocate a significant budget to deal with the problem, that means that there wasn't really any flooding, it's just that there's money available for people to shout "Flood!"
1) Nobody is claiming that climate doesn't change - the debate is over the source(s) of that change.
I still see lots of people claiming that it's mostly due to the urban heat island.
2) Flooding is a present problem that causes damage, and is quite demonstrable as to its immediacy and even its sources. AGW theory on the other hand promises problems later down the road... maybe, well, if their models are proven to be correct.
Try again?
Well AGW theory promises problems like flooding, and preparing for AGW can help us mitigate or even reduce those problems.
As for your skepticism over the theories, the only way to truly prove the models correct is to wait for the consequences to happen, and at that point it might be too late to act.
For a country the size of the US $1 billion is minuscule, even if the skeptics were right and the science was shoddy group think and the models were wildly inaccurate, the potential size of the problem is so big that this would still be a good investment.