BANGOR DAILY NEWS • December 4, 2023
Jim Hansen, the climate scientist who delivered the original wake-up message to the U.S. Congress in 1988, has used new data to work out the “equilibrium climate sensitivity.” The news is bad. The ECS — how much warming we will get in the long run from doubling the amount of carbon dioxide in the atmosphere — is much higher than we thought. We were expecting an extra 3 degrees; we will get five. Hensen also reckons that all the visible pollution we put into the sky was cooling the planet by reflecting incoming sunlight back into space. But we are rapidly cleaning it up, because it’s bad for people’s lungs. That means we are rapidly losing our protective global sunscreen. Hansen suspects these changes have lost us 1 degree’s worth of cooling — and in terms of average global temperature a degree of lost cooling is just as bad as a degree of extra warming. It may be time to start taking this climate stuff seriously. ~ Gwynne Dyer