As reported by Kenneth Richard, NoTricksZone, a new study (Stallinga, 2020 Comprehensive Analytical Study of the Greenhouse Effect of the Atmosphere) assesses the climate sensitivity to rising CO2 concentrations is just 0.0014°C per ppm.
Dr. Peter Stallinga has published a comprehensive analysis of the Earth’s greenhouse effect. He finds an inconsequential role for CO2. Doubling CO2 from 350 to 700 ppm yields a warming of less than 0.5°C. Feedbacks to warming are likely negative, as adding CO2 may only serve to speed up natural return-to-equilibrium processes. As for absorption-re-emission perturbation from CO2, “there is nothing CO2 would add to the current heat balance in the atmosphere.” (Read full paper , caution lots of math)
Paper’s conclusion: “we find that the alleged greenhouse effect cannot explain the empirical data—orders of magnitude are missing. Henry’s Law—out-gassing of oceans—easily can explain all observed phenomena. Moreover, the greenhouse hypothesis cannot explain the atmosphere on Mars, nor can it explain the geological data, where no correlation between CO2 and temperature is observed. Nor can it explain why a different correlation is observed in contemporary data of the last 60 years compared to historical data (600 thousand years). We thus reject the anthropogenic global warming (AGW) hypothesis, both on basis of empirical grounds as well as a theoretical analysis.”