@113 Robert Wagner “Even if I give you that point [that man emits far more CO2 than volcanoes do] there is no causal effect of CO2 driving temp higher. Going back 650 million years, high levels of CO2 NEVER caused temperatures to make it above 22 degree C.”
http://csccc.fcpp.org/files/f13.jpg
“What makes you think this time is different?”
You seem to imply that CO2 did cause the temperature to go as high as 22 C., but not higher. I don’t think you mean that, but even if you don’t, you sound like you think 22 C. isn’t much. Actually it’s a lot, an 8-degree rise. I’d be surprised to see more than a 2-degree rise by the end of the century or any “foreseeable” date later than that.
8 degrees is at the high end of the IPCC projections. It assumes high positive feedback, but there have been findings that the feedback is even lower than the low end of the IPCC range of assumptions. Even without any special findings, there’s the simple fact that we’ve seen less warming since the 1800s than we should have seen with *NO* positive feedback.
With no positive feedback, we’d need 3,000 ppm CO2 to raise the temperature by 8 degrees, and that’s without fudging in any “less” as above. There’s no chance at all that we’d make the CO2 level that high. However, if we put it up to about 1,000 ppm, we could, if the feedback is non-negative, get a 4-degree rise, and I guess that would be trouble. I don’t say that any of this 1 degree or 4 degrees will happen. I say that the alarmists have a non-negligible case, and I say that *if* they are right, the question comes down to the cost of letting the temperature go up that high vs. the cost of cutting emissions, and, at present, I think the 2nd cost is higher. Now, naturally, we’re going to have – we do have – many politicians claiming that it’s not higher, but we know how well their projects work, e.g., look at welfare.
