Lifted from the Weasel King

[james_davis_nicoll]

If this error turns out to be an actual mistake Reinhart-Rogoff made, well, all I can hope is that future historians note that one of the core empirical points providing the intellectual foundation for the global move to austerity in the early 2010s was based on someone accidentally not updating a row formula in Excel."

Comments

[(Anonymous)]

"Sensitivity _is_ low; we can tell that because the paleoclimate record doesn't bounce all over the place, it's relatively stable."

Actually we can't. Uncertainties in our estimates of paleoclimatic forcing plus uncertainties in paleotemperatures give a wide range of possible senstivities.

Volcanic eruptions are also hard to use. There's a strong sublinear relation between sensitivity and resulting temperature change in these transient forcings. Or to put it more concretely, double the sensitivity does not mean nearly double the resulting temperature change for something like Pinatubo. Thus estimates of this kind wind up with a long tail, which is why early statistical work circa 2000 could not rule out with 95% confidence sensitvities as high as 10 C.

I don't work in this field any longer, but my guess is that temperatures are being kept at the low end of predictions becuase China and other countries are systematically underestimating their aerosol production. An atmospheric chemist of my acquaintence said he couldn't reconcile the data for pacific aerosol counts except by doubling the Chinese numbers.

William Hyde

[mmcirvin.livejournal.com]

That sounds reminiscent of what might have been going on from 1940-1970.