Yes, there is evidence that a price on carbon does reduce greenhouse gases. The debate—and I'm not the one who will settle that debate—is whether it's too high a price to pay to reduce greenhouse gases or whether it's acceptable. It's up to people such as you to determine that. However, there is evidence to show that if you put a price on greenhouse gas emissions, all other things being equal, emissions will tend to go down.
The issue is whether you have to put a low price or a very high price. It is not always an immediate response. It involves capital expenditures, and people have fixed assets that they replace, so the time lag to respond to that signal can be long, but it does, indeed, reduce greenhouse gas emissions.