New study settles it: Global Warming and the pause was driven by changes in cloud cover, not CO2

That’s it: It was 4% cloudier in 1985, then roughly the same after 2000 — that’s the Pause and the Cause

A new paper in Russian, by OM Pokrovsky, shows that global cloud cover decreased markedly from 1986 to 2000. This is a very large decline in terms of the planetary atmosphere. Pokrovsky uses ISCCP satellite data (the “International Satellite Cloud Climatology Project” — a US program). It’s the best cloud data there is. The effects of clouds are so strong that most of the differences between IPCC-favoured-models comes from the assumptions the models make about clouds. Cloud feedbacks are the “largest source of uncertainty”. [IPCC, 2007]

Clouds cover two-thirds of the Earths surface, reflecting around 30% of the total energy from the Sun back to space. A small change in cloud cover can easily warm or cool the planet, like a giant pop-up shade-sail.

This, on its own, explains all the warming that occurred from 1986 – 2000. It explains the pause. We don’t know why clouds decreased, but we know it wasn’t due to CO2, which kept rising relentlessly year after year, and even faster after the turn of the century.

Something else is driving cloud formation, or density or […]