Claim: Late 20th Century cycles in temperature, CO2, and sea surface temperatures (SSTs) show that CO2 still lags temperature, and therefore cannot be the cause of modern global warming.
Why This Claim is Wrong: Humlum et al. (2013) and earlier Humlum et al. versions are the source of this claim. Their analysis is simplistic and deeply flawed, attempting to take very short term rates of change of these data and because they do not see a simple pattern of CO2 peaking earlier than short-term peaks in SST's and global atmospheric temperatures, conclude there's no cause/effect. This is thoroughly debunked by climate scientists from the IPCC at RealClimate.org here. By choosing an analysis method which ignores trends caused by human activities, they seem to think it is profound that they do not see obvious anthropogenic effects left in their data(!) They also ignore that rising SST's have a feedback on CO2 in the atmosphere in that hotter SST's will inhibit CO2 uptake by the ocean, leading to higher CO2 left in the atmosphere especially during El Nino's. They also ignore the seasonal biological CO2 cycle. Adding very short term noise from the effects listed above and more, will destroy that obvious correlation with anthropogenic causes, as explicitly demonstrated here. The clear case that climate change is real and human-caused is in the simultaneous rise in atmospheric CO2 with known rates of human-caused CO2 emission, rising troposphere temperatures together with cooling of the stratosphere, and many more lines of evidence summarized here.
| In Short: It's junk science, using completely unsuitable statistics which are controlled by noise to then make unjustified claims about CO2 causation of climate change. One wonders why the paper's referee did not call attention to the these obvious flaws. The referee process is usually good, but not always. It's also concerning that the authors have collaborations with the Heartland Institute. |