Predicting Global Warming for Dummies
Climate scientists use supercomputers and extremely complicated models to predict the future climate, but there is a shortcut that can be used to predict average global warming. The key to that shortcut is the following simple formula: $$ \Delta T_{anom.} = \frac {ECS \times ( C_{atm.} – 280 )} {280} \: – \: \psi,$$ in which \(\Delta T_{anom.}\) is the average temperature anomaly (or average global warming), \(ECS\) is “Equilibrium Climate Sensitivity”, \(C_{atm.}\) is atmospheric carbon (in ppm CO₂ equivalent), and \(\psi\) (from Greek ψῦχος, meaning “cold”) stands for various cooling effects. If you have the values of the variables...
Some Further Comments on Climate Sensitivity and Warming Estimates
While preparing an update of Carbon-Neutrality by 2050 (by far the most accessed page in this blog), I had another look at (equilibrium) climate sensitivity (ECS), a topic about which a wrote a few times before. ECS is the expected global temperature anomaly (i.e., the expected global average of warming) at twice the pre-industrial level of greenhouse gases (mainly CO₂) in the atmosphere (i.e., 560ppm, as “pre-industrial” is set at 280ppm). The currently most widely accepted estimate of ECS is that by Steve Sherwood and colleagues, who suggest average warming of 3.1°C (median; 66% uncertainty range: 2.6~3.9°C; 95%: 2.3~4.7°C). However,...