Another silly debate around the IPCC report
News stories have been reporting that the IPCC will make a statement about the relation between global warming and hurricanes:
During marathon meetings in Paris, the Intergovernmental Panel on Climate Change approved language that said an increase in hurricane and tropical cyclone strength since 1970 “more likely than not” can be attributed to man-made global warming, according to Leonard Fields of Barbados and Cedric Nelom of Surinam.
Some commenters have been arguing that this statement fundamentally disagrees with a recent statement by the World Meteorological Organization (WMO). The implication is that this disagreement shows that the IPCC process cannot be trusted — and therefore, we should not believe the IPCC’s conclusions.
Let’s compare their statements. In the IPCC’s language, “more likely than not” means something like a 51% chance — a smidge more than a coin flip. The alternative phrasing by the WMO is that while there is evidence “both for and against” a connection, “no firm conclusion can be made at this point.” (PDF here).
To my eye, these statements mean pretty much the same thing. But like the hockey stick debate, I suspect that doesn’t really matter much. What matters is that this mole hill will be blown up to a mountain by advocates who want to use this difference to launch attacks on the IPCC.
Sadly, this delightfully noisy but substance-free argument will take away from the IPCC’s most important result: the Earth just keeps getting warmer, and we’re primarily to blame.
(Also see my previous post on why we should trust the IPCC here.)