Climate science has been thrown into disarray by the hiatus, disagreement between climate model and instrumental estimates of climate sensitivity, uncertainties in carbon uptake by plants, and diverging interpretations of ocean heating (in the face of a dearth of observations). ‘Certainty’ arguably peaked at the time of the AR4 (2007); perception of uncertainty is arguably greater than any time since the FAR (1991). Yes of course we know more about the climate system than we did in 1991, but more knowledge about the complex climate systems opens up new areas of ignorance and greater uncertainty.
In context of the way climate sensitivity is defined by the IPCC, uncertainty in climate sensitivity is decreasing as errors in previous observational estimates are identified and eliminated and model estimates seem to be converging more. Climate model simulations, when compared with 21st century observations seem to be running too hot, giving creedence to the lower observation-based sensitivity values.
What do the lower values of climate sensitivity imply for policy? Well slower values of warming make it easier to adapt, and provide time to develop new technologies and new policies. But the true believers such as Mann et al. call adaptation, developing new technologies and policies as ‘inaction.’ The policy logic apparent in the essays critical of my op-ed are rather naive.
So we are left with science in disarray and naive logic regarding policy. And the ‘warm team’ wonders why people are yawning?
She should cite my piece on the precautionary principle.