I've noticed that most of the plans to fight global warming involve high taxes and eventually controlling our actions and what we can buy, since we are too stupid or selfish to control ourselves.
We don't need a treaty to force us to fix things. We already are doing things to fight it. Car emissions have been cut the past few decades. While it's true that some gas guzzlers exist, there are plenty of vehicles, including some SUVs, that get good mileage and quite a few vehicles that get great mileage. On top of that, the gas guzzlers of today produce fewer emissions than those of the '60s. We have cut global warming gases in other ways too numerous to mention here.
As others have stated, not all scientists agree on global warming. Recently, two books written by climate scientists came out to say global warming is natural. One ice researcher said the ice isn't melting, it's moving. While these scientists use facts and logic, those on the other side totally discount those that disagree with them by saying they work for big corporations, therefore implying that they are lying.