Svetlana, this was actually a reasonably good paper that you sited, unlike that drek provided by Nathan
.
The problem with weather modeling is that it's non-deterministic ( stochastic ) and we have no good way for modeling is conclusively.
Even IPCC statement does not say that anthropogenic global warming is a certainty, i believe they give it a 90% chance.
People like Al Gore don't help the cause of GW supporters too much, as his statement and movie are total bullshit.