The only people who deny the warming are people who think scientists are being paid by crazy environmentalists to lie. Most of the warming is happening at the poles, where it's not so easy to see it in St. Louis. Sea levels are rising, droughts are getting longer and their effects are getting worse, and so on. The evidence is everywhere.
The problem is that the Earth has been warmer before, and even warmer recently (the climate in Europe until about 1300 was warmer than it is now). The debate is over how much of it now is due to humans, and this debate swirls around greenhouse gases like carbon dioxide. If C02 is responsible, we can and should do something about this, because the cost of ignoring the problem could be enormous.