Guest commentary by Kevin Trenberth and John Fasullo
The hype surrounding a new paper by Roy Spencer and Danny Braswell is impressive (see for instance Fox News); unfortunately the paper itself is not. News releases and blogs on climate denier web sites have publicized the claim from the paper’s news release that “Climate models get energy balance wrong, make too hot forecasts of global warming”. The paper has been published in a journal called Remote sensing which is a fine journal for geographers, but it does not deal with atmospheric and climate science, and it is evident that this paper did not get an adequate peer review. It should not have been published.
The paper’s title “On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth’s Radiant Energy Balance” is provocative and should have raised red flags with the editors. The basic material in the paper has very basic shortcomings because no statistical significance of results, error bars or uncertainties are given either in the figures or discussed in the text. Moreover the description of methods of what was done is not sufficient to be able to replicate results. As a first step, some quick checks have been made to see whether results can be replicated and we find some points of contention.
There has been a lot of hype from the denialist camp on this paper as though one paper could completely upend all the previous work. Not too likely.
Getting a paper published in an inappropriate journal is one thing to worry about with a new paper. If this was so important, why not a higher profile place (remember Nature published a naturopathic paper why back when, just for the controversy).
For another thing, for this groups model to work, clouds have to cause weather, not weather causing clouds. So I guess a hurricane is caused by the clouds that form rather than the weather system driving it? That is what is meant by a forcing. Carbon dioxide is a forcing because it causes the temperatures to go up.To call clouds a forcing seems to completely at odds with what we expect that it requires greater proof than assertion or model building.
Denialists hate models, Except this paper is all based on models,ones that have apparently been cherry-picked to give the results desired by the researchers. As RealClimate states:
To help interpret the results, Spencer uses a simple model. But the simple model used by Spencer is too simple (Einstein says that things should be made as simple as possible but not simpler): well this has gone way beyond being too simple (see for instance this post by Barry Bickmore). The model has no realistic ocean, no El Niño, and no hydrological cycle, and it was tuned to give the result it gave. Most of what goes on in the real world of significance that causes the relationship in the paper is ENSO. We have already rebutted Lindzen’s work on exactly this point. The clouds respond to ENSO, not the other way round [see: Trenberth, K. E., J. T. Fasullo, C. O’Dell, and T. Wong, 2010: Relationships between tropical sea surface temperatures and top-of-atmosphere radiation.Geophys. Res. Lett., 37, L03702, doi:10.1029/2009GL042314.]
No error bars or statistical significance are other weaknesses. The fact that others are stating that there is not enough information to replicate their work really makes this a worthless paper, even if it was demonstrating something extra-ordinary.
And finally, rising carbon dioxide levels have much greater impact than just raising temperatures. We must do what we can to lower our production.