On the list of debunked myths that “skeptics” like to promote in an attempt to downplay the significant role of CO2 as a greenhouse gas is the old “More CO2 has little effect” card; Nova’s no exception with her “Carbon dioxide is already absorbing almost all it can” post. This has been debunked many times over. Interestingly in the early 1900’s it was a valid skeptical argument, but it was rebutted and ever since climate scientists knew better.
That doesn’t stop political bloggers from dragging out old myths. Nova goes on to confuse the issue even further.