Marc, you're right that increasing the cost of electricity is a nonstarter for many important reasons. However, you needn't worry about the cost of wind. It's actually cheaper than natural gas when you consider the cradle-to-grave Levelized Cost of Electricity. Natural gas is then cheaper than coal, which is cheaper than nuclear.

The way carbon dioxide traps heat, every time its atmospheric concentration is doubled, it results in a given amount of warming. So if it increased from 180 to 280 ppm over a period of 10,000 years as we came out of the last ice age as scientists say, that's an increase of 55%. Temperatures climbed by 7 or 8 degrees F. We've already increased CO2 from that point another 45% in a relatively brief 150 years, and temperatures have risen over 2 degrees F.

There is not a single scientific source you can point to that will agree with your assertion that CO2 levels rising above 250 ppm would have no impact.