By themselves, sunspots don't prove or disprove the anthropogenic global warming hypothesis. But there are other things that do, such as the fact that changes in levels of carbon dioxide lag temperature changes by about 800 years, the fact that temperatures and levels of carbon dioxide have both been significantly higher than now over the last 10,000 years (and have been much higher than now over the past 300 million years,) and finally the fact that the contribution of carbon dioxide to greenhouse warming asymptotically approaches zero as its level increases—and we're way past the level where any change to the amount of atmospheric carbon dioxide has any meaningful effect either way (it would take a massive reduction to levels way below any that have been seen for many millions of years to change that.)
Please explain this, it's not making sense to me. By the contribution are you talking about the temp change?, or the change in the derivative deltaT/concentration with an increase in concentration?
If you'd quote a source that would be great...considering that this can almost be treated as a colligative property in the atmosphere and i have trouble believing that the derivative would approach zero at such a low concentration. Especially because there are huge differences in the absorption between 70% concentration by moles and 80% concentration by moles in CO2....which is way beyond anything in the atmosphere by a factor of millions.