Telling guilt from global warming

Climate Etc

Judith Curry draws a radical conclusion from this radical paper. The authors claim that climate forcings from both human influence and natural variation are likely of similar magnitude, which is the first time since the IPCC was created that the climate establishment has expressed that possibility. Then they admit that telling the difference between them is difficult (the science is not settled). That’s the second time that’s been said (the first time was in an early IPCC report). Since “human influence” has become a hot-button code word for guilt, perhaps the guilt might now subside. Finally, Judith has a plea for the IPCC authors: “No more ‘unequivocals’ or ‘very likelys’ in the AR5, please.” Amazing — you must read this and share it with everyone you know or don’t know. It’s sober and persuasive evidence that a tide is turning — a belief in dangerous warming no longer holds a trump card in climate studies. Make the politicians face this new scientific reality or they’ll go on for years with their ETS and carbon taxes – h/t Barry Brill

Separating natural and anthropogenically-forced decadal climate variability

The issue of separating natural from anthropogenically forced variability, particularly in context of the attribution of 20th century climate change, has been a topic of several previous threads at Climate Etc. The issue of natural vs anthropogenically forced climate variability/change has been a key issue of contention between the climate establishment and skeptics. There are some encouraging signs that the climate establishment is maturing in their consideration of this issue. Continue Reading →