As negotiators from 195 countries gather in Paris this month to hammer out a global agreement to limit climate change, their discussion will be guided in part by the findings of the Intergovernmental Panel on Climate Change. Those findings are contained in the IPCC’s fifth Assessment Report, or AR5, a comprehensive, rigorously assembled document that provides in-depth information not only about climate science but the options for adapting to and preventing climate change.
Notwithstanding the attention given to AR5 when it was released beginning in September 2013, I frequently hear claims that are not supported by AR5. So, on the verge of the historic negotiations in Paris, I would like to take this opportunity to respond to some of the more frequent misconceptions about climate change.
Global temperatures are continuing to increase. Data from AR5’s Working Group I showed that average global temperatures appeared to have temporarily leveled off after an unusual peak in 1997. (I say “appeared” because more recent statistical analyses not included in AR5 indicate that there was no level-off.) This, in turn, has been cited as an acknowledgement by the IPCC that warming is no longer increasing. But that is not what the IPCC conveyed.