If you run in the right circles, you might encounter someone who breathlessly tells us that the downward trend in estimates of climate sensitivity (how much added warmth comes from added atmospheric CO2) got turned around by a new study in Nature Climate Change, and we're back to a best estimate of Equilibrium Climate Sensitivity (ECS) of 3.0 for doubled CO2. That would indeed appear to be a plausible interpretation of the study. But the study itself is badly flawed, as climate sensitivity … [Read more...]