However, there are multiple fundamental problems with the claim including:
1. As stevengoddard.com points out in "Junk Science Award For The Evening"
"Over the deade the authors examined (2000 to 2010), the average level of the gas (CO2) in the atmosphere went up by 22 parts-per-million. And the time series shows a steadily rising trend in its impact, layered on top of the seasonal changes. By the end of that period, the gas was retaining an extra 0.2 Watts for every square meter of the Earth’s surface compared to the start.
Still, it seems worth noting that the continued increase in greenhouse energy retention measured during this time coincides with a period where the Earth’s surface temperatures did not change dramatically. All that energy must have been going somewhere. [i.e. to space] "
The authors started in the 2000 La Nina, and ended at the 2010 El Nino – when troposphere temperatures were half a degree warmer. Then they noticed that there was slightly more downwelling long wave radiation [DWLR], which they blamed on increased absorption from the increase in CO2.
The increase in DLWR was due to the warmer troposphere during the El Nino. Warmer air emits more longwave radiation. The higher concentration of CO2 will also emit more DLWR radiation, but that is not due to increased absorption. I don’t know how scientists can get any more clueless than that.
Indeed, the authors admit in the abstract below that the CO2 contribution to the alleged overall trend of downwelling longwave radiation is a mere 10% of the total. So what caused the other 90%?
However, per the (debunked) IPCC formula, the rise in CO2 from 369.52 ppm in 2000 to 389.85 ppm in 2010 "would" have "trapped"
5.35*ln(389.85/369.52) or 0.29 W/m2
Thus even if one believes the IPCC formula and this new paper's assumptions (including extensive computer modeling in the new paper), the IPCC formula exaggerates CO2 surface radiative forcing by 45% over the observations.
3. Thirdly, the peak emission spectra of CO2 is at 15 microns, which by Wien's displacement law is equivalent to a blackbody radiating at -80C. Per the second law of thermodynamics, a low temperature/frequency/energy body at -80C cannot warm a higher temperature/frequency/energy body at 15C (Earth).
4. Rather, the entire 33K greenhouse effect is entirely explained by the Maxwell/Carnot/Clausius atmospheric mass/gravity/pressure theory and the 'greenhouse equation.' Increased CO2 instead facilitates loss of outgoing IR radiation to space, as has been observed by an increase in OLR (Outgoing Longwave Radiation) over the past 60+ years, opposite to the predictions of the alternative radiative forcing greenhouse theory.
The claim that the warming 2000-2010 is from CO2 confuses cause with effect. Warming of the atmosphere due to internal variability, ocean oscillations, cloud cover changes, solar amplification mechanisms, etc. secondarily warm the CO2 in the atmosphere increasing the 15 micron IR radiation observed from increased levels of CO2.