It’s hard to understand what the U.N. Intergovernmental Panel on Climate Change is yammering on about.
The IPCC -- which has released its latest climate assessment in three huge installments -- uses confusing language to describe how certain it is about its findings. This could be misleading the public into thinking scientists are less certain than they really are about global warming, according to a new study.
Consider this statement from the first installment of the IPCC report, which came out in September: “It is very likely that the number of cold days and nights has decreased and the number of warm days and nights has increased on the global scale.”
By using the phrase “very likely,” the scientists mean that there’s a 90 to 99 percent likelihood that the statement is true. But when normal people read "very likely" in a statement like that, they think the IPCC’s scientists are just 55 to 90 percent confident in it, according to the new study, which was published in the journal Nature Climate Change.
Here are the seven main descriptors that IPCC report authors are told to use, and what percentage of certitude they're meant to communicate: