The deniers quote an article "No Rise of Atmospheric Carbon Dioxide Fraction in Past 160 Years, New Research Finds" without understanding the difference between the Amount of CO2 in our atmosphere and the Fraction of human-generated carbon that remains in the air.
Here's what the article says...
"... Most of the carbon dioxide emitted by human activity does not remain in the atmosphere, but is instead absorbed by the oceans and terrestrial ecosystems. In fact, only about 45 percent of emitted carbon dioxide stays in the atmosphere. ..."...and from this, the deniers conclude that man-made global warming is a hoax.
This is a stupid conclusion. 45% of the carbon emitted by human activity is a heck of a lot of carbon. The "Fraction" referred to in the title is the fraction of the total emissions that remain in the atmosphere, not the fraction of the atmosphere that is CO2.
Indeed, the study does not say anything about the undisputed fact that global atmospheric CO2 levels have increased. But that doesn't stop the deniers from stupidly citing this study in support of their claim.
Reasonable people may question the best way to address this problem, but the deniers have once again shown they don't know science and cannot be trusted.