I see that RC has a post today that begins “when global warming inactivists need to trot out somebody with some semblance of scientific credentials . . .”

I hope you’ll express your concerns about tone there as well . . . Thanks!

Sure, if by AGW Douglas means that the increase in greenhouse gases emitted by humans has effects of the climate system, and among these effects include a long-term warming of the globe, then nothing I’ve posted is inconsistent with this perspective of AGW.

Now given that, there are a lot of things that might be observed which are inconsistent with the specific predictions of climate models on the short (and long-term). We’ve discussed the short term frequently here. But I don’t put much faith into, for instance, predictions for crop yields in Zimbabwe in 2085.

My interest here has continued to be in predictions, and especially their usefulness in decision making, given AGW (as Douglas puts it).

Hope this clarifies.

Could you please clarify your statements in response to Douglas?

By “‘inconsistent with’ AGW” do you mean inconsistent with ‘reasonable’ projections of average global temperature OBSERVATIONS?

By “‘inconsistent with’ predictions” do you mean inconsistent GCM projections?

Both seem to be predictions, subject to uncertainty.

Len Ornstein

I do want to emphasize that there is an important distinction between being “inconsistent with” predictions and “inconsistent with” AGW as you write.

Nothing in my comments should be taken as being “inconsistent with” AGW . . .

The abstract reads

“The total heat gained by the North Atlantic Ocean over the past 50 years is equivalent to a basinwide increase in the flux of heat across the ocean surface of 0.4 ± 0.05 watts per square meter. We show, however, that this basin has not warmed uniformly: Although the tropics and subtropics have warmed, the subpolar ocean has cooled. These regional differences require local surface heat flux changes (±4 watts per square meter) much larger than the basinwide average. Model investigations show that these regional differences can be explained by large-scale, decadal variability in wind and buoyancy forcing as measured by the North Atlantic Oscillation index. Whether the overall heat gain is due to anthropogenic warming is difficult to confirm because strong natural variability in this ocean basin is potentially masking such input at the present time.”

“Inconsistent with AGW” might be an appropriate phrase to describe this paper and confirms some of the quotes from Knutson that you give.

If inconsistencies exist, but are either not noticed or are denied, then appropriate steps to improve models will likely not be undertaken. In most fields, modelers take even apparent inconsistencies between the central tendencies of their predictions and the phenomena they wish to observe quite seriously.

Hopefully, climate modelers are able to identify and admit inconsistencies in private, even if they wish to prevent others from discussing them in public.