Roger Pielke Sr.: Further Evidence Of The Failure Of Multi-Decadal Regional Climate Predictions …

In response to the post on Watts Up With That on March 12 2012 titled Climate modeling turkey shoot, western style Dr. Nathan Schmidt, a Senior Water Resources Engineer at Golder Associates Ltd in Edmonton, Alberta alerted me to a very enlightening e-mail that was exposed in one of the Climategate e-mails.

The e-mail is from Jagadish Shukla of COLA with respect to the IPCC report. Dr. Shukla is an internationally well-respected climate scientist. The e-mail reads [highlight added]

date: Wed, 13 Feb 2008 16:46:33 -0500 from: J Shukla subject: Future of the IPCC: to: IPCC-Sec

Dear All,

I would like to respond to some of the items in the attached text on issues etc. in particular to the statement in the section 3.1.1 (sections 3: Drivers of required change in the future).

“There is now greater demand for a higher level of policy relevance in the work of IPCC, which could provide policymakers a robust scientific basis for action”.

1. While it is true that a vast majority of the public and the policymakers have accepted the reality of human influence on climate change (in fact many of us were arguing for stronger language with a higher level of confidence at the last meetings of the LAs), how confident are we about the projected regional climate changes?

I would like to submit that the current climate models have such large errors in simulating the statistics of regional (climate) that we are not ready to provide policymakers a robust scientific basis for “action” at regional scale. I am not referring to mitigation, I am strictly referring to science based adaptation.

For example, we can not advise the policymakers about re-building the city of New Orleans – or more generally about the habitability of the Gulf-Coast – using climate models which have serious deficiencies in simulating the strength, frequency and tracks of hurricanes.

We will serve society better by enhancing our efforts on improving our models so that they can simulate the statistics of regional climate fluctuations; for example: tropical (monsoon depressions, easterly waves, hurricanes, typhoons, Madden-Julian oscillations) and extratropical (storms, blocking) systems in the atmosphere; tropical instability waves, energetic eddies, upwelling zones in the oceans; floods and droughts on the land; and various manifestations (ENSO, monsoons, decadal variations, etc.) of the coupled ocean-land-atmosphere processes.

It is inconceivable that policymakers will be willing to make billion-and trillion-dollar decisions for adaptation to the projected regional climate change based on models that do not even describe and simulate the processes that are the building blocks of climate variability. Of course, even a hypothetical, perfect model does not guarantee accurate prediction of the future regional climate, but at the very least, our suggestion for action will be based on the best possible science.

It is urgently required that the climate modeling community arrive at a consensus on the required accuracy of the climate models to meet the “greater demand for a higher level of policy relevance”.

2. Is “model democracy” a valid scientific method? The “I” in the IPCC desires that all models submitted by all governments be considered equally probable. This should be thoroughly discussed, because it may have serious implications for regional adaptation strategies. AR4 has shown that model fidelity and model sensitivity are related. The models used for IPCC assessments should be evaluated using a consensus metric.

3. Does dynamical downscaling for regional climate change provide a robust scientific basis for action?

Is there a consensus in the climate modeling community on the validity of regional climate prediction by dynamical downscaling? A large number of dynamical downscaling efforts are underway worldwide. This is not necessarily because it is meaningful to do it, but simply because it is possible to do it. It is not without precedent that quite deficient climate models are used by large communities simply because it is convenient to use themIt is self-evident that if a coarse resolution IPCC model does not correctly capture the large-scale mean and transient response, a high-resolution regional model, forced by the lateral boundary conditions from the coarse model, can not improve the response. Considering the important role of multi-scale interactions and feedbacks in the climate system, it is essential that the IPCC-class global models themselves be run at sufficiently high resolution.

Regards, Shukla

This e-mail further illustrates what I discussed yesterday in my post

Climate Science Malpractice – The Promotion Of Multi-Decadal Regional Climate Model Projections As Skillful

Those who present multi-decadal regional climate model results to the impact (stakeholder) community without also communicating that they have no predictive skill (or provide evidence to the contrary) are quilty of climate science malpractice.

Roger Pielke Sr.

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