New evidence from fossil cores supports the idea that more greenhouse gases means warmer temperatures in a more or less linear way.

During the Pliocene, the Earth’s temperature was often several degrees higher than in pre-industrial times, while atmospheric CO2 levels were around 350-450 parts per million (ppm), similar to the levels reached in the past few years (400 ppm).

By studying the relationship between CO2 levels and climate change during a warm period in the Earth’s history, the scientists have been able to estimate how the climate will respond to increasing levels of CO2, a parameter known as climate sensitivity.

The findings suggest that climate sensitivity was similar in a warmer world to other times – allaying concerns that warming could produce positive feedbacks that would accelerate warming above that expected from modelling studies.

I wouldn’t call this great news, but it does suggest we will have a chance to adjust to gradual change, rather than being blind-sided by some sudden catastrophic change.