Perhaps.
"To sum up--there's no smoking gun to prove beyond doubt we are already changing the climate. But, if current trends continue, the amount of CO2 entering and accumulating in the atmosphere will go on rising. Given the vast reserves of fossil fuels, sooner or later we will put enough CO2 into the atmosphere to force a climate change. Just what this climate change will be, nobody knows. But once we have changed the atmosphere, it will take hundreds of years to return to the way it was before the industrial revolution. "
http://www.pbs.org/wgbh/warming/etc/faqs.html

And these guys are still clinging to the Hockey Stick and other false information. Where they get "it will take hundreds of years to return to the way it was before the industrial revolution" might be fun to track down. Of course, why you would want CO2 to be at levels Pre-industrial revolution is another fasinating question. Even the Lefties admit there is no smoking gun- of course they hate guns in general and think we already doomed because we are stupid enough to wait for evidence. But to there credit they did mention that Earth was 20 degrees warmer than it is today. And made it somewhat clear that "alternative sources of energy" [other nuclear] is completely impractical.