Talk:Iris hypothesis

Looking at http://earthobservatory.nasa.gov/Study/Iris/ it appears clear that the Iris Hypothesis suggests "that the warmer the cloudy region, the less cirrus you get" and therefore the more infrared leakage into space. The article currently talks about "visible-length radiation leakage" which appears incorrect.

Looking at http://earthobservatory.nasa.gov/Study/Iris/iris2.html, the "fallacy" was found to be the finding that "clouds are much more reflective (51 percent instead of 35 percent) and somewhat weaker in their greenhouse effect than Lindzen’s model predicts". So the current line "The fallacy was that more infrared radiation would be trapped, cancelling out the cooling from the visible-wavelength radiation leakage" does not appear to be correct.

In any case, is "fallacy" the correct word to use? At http://earthobservatory.nasa.gov/Study/Iris/iris3.html it says "At present, the Iris Hypothesis remains an intriguing hypothesis—neither proven nor disproven". The article at present appears to assume that the hypothesis is disproven by using the word "fallacy". Is it even reasonable to use the adjective "partially-discredited" if the jury is still out? What do people think?

Is this related?

I was trying to research this story from NPR and this page was the closest thing I could find.. is this related, and if so then does that lend some credibility to the Iris hypothesis? I realize that cirrus clouds aren't in the stratosphere but the mechanisms described in the NPR story sound pretty similar (fewer clouds in the tropics, etc.) --Lewis (talk) 06:56, 29 January 2010 (UTC)

Spencer et al evidence disputed by Lin et al

The last phrase of this article notes that Spencer et al present evidence in favor of the iris hypothesis, but it may be worth noting that this evidence is disputed by Lin et al, who, using a more advanced model that takes into account interannual correlations, find a positive feedback that does not show up in the short term. They note that using short term observations and runs may produce feedback estimates that are significantly in error.

Lin, Bing, Qilong Minb, Wenbo Sunc, Yongxiang Hua and Tai-Fang Fan, 2010a, Can climate sensitivity be estimated from short-term relationships of top-of-atmosphere net radiation and surface temperature?, Journal of Quantitative Spectroscopy and Radiative Transfer, Article in Press, doi:10.1016/j.jqsrt.2010.03.01

Still in press last time I checked, but I'm pretty sure that it did already pass peer review.

EDIT: Link http://linkinghub.elsevier.com/retrieve/pii/S0022407310001226

—Preceding unsigned comment added by 95.36.46.175 (talk) 03:33, 30 August 2010 (UTC)

I would say a bigger concern is that the so-called evidence is by Spencer and Lindzen. Even without Lin's objection, if all the evidence for the iris hypothesis comes well-known climate skeptics then this is no different from putting foxes in charge of the hen house. --Vaughan Pratt (talk) 07:57, 7 December 2010 (UTC)

Consensus view?

I am not aware of a specific consensus view on the Iris effect. If there is the claim should be referenced. —Preceding unsigned comment added by 131.230.109.78 (talk) 18:41, 22 February 2011 (UTC)

Can we bear to say its dead?

This thing had its brief time in the sun but is now effectively dead. Can we bear to say so? We'd need an RS, I suppose. That everyone quietly ignores it isn't enough? William M. Connolley (talk) 17:37, 11 January 2014 (UTC)

Would be good to have an update on this. Pinging User:Femke and User:RCraig09 who might be in the know. I came to this page via my work at global warming controversy. EMsmile (talk) 09:11, 15 November 2023 (UTC)

In general, even a disproven theory can warrant an article if it's a notable theory. This article now reads like a literature review rather than an encyclopedia article, but I don't think that's enough criterion to delete. Averaging 24 views per day over the last year, I don't see it as a big issue. Maybe a critical hatnote is most appropriate. —RCraig09 (talk) 16:18, 15 November 2023 (UTC)

Thank you, RCraig09. I agree with you. For that reason, we still have miasma theory even though it's completely disproven, and the article explains that. I wonder if there are recent publications out there which refute the Iris hypothesis quite clearly. If so, that could be added in to make this article more useful. I am not into the topic deeply enough to do such a literature search. Pinging User:William M. Connolley for comment. - Also wondering if the Iris hypothesis is worth mentioning in global warming controversy or not really (keeping in mind that we are currently shrinking down global warming controversy and might completely merge it to elsewhere in the end). EMsmile (talk) 10:10, 16 November 2023 (UTC)

I've added some info from Kevin Trenberth's memoirs but I am not totally satisfied with the end result yet. Also would like to get a URL for his memoirs (currently only have a link to a dropbox account). EMsmile (talk) 11:45, 4 December 2023 (UTC)

I find the whole thing difficult to write in language that is clear to lay persons (it is not even clear to me either). Kevin pointed out in his memoirs "Most scientists are in an ivory tower and do not take on those who promote erroneous and poor-quality material." So this is tricky. Pinging User:Bikesrcool in case they can help. EMsmile (talk) 11:54, 4 December 2023 (UTC)

For context it might be helpful to review IPCC AR6 WGI Chapter 7 Section 7.4.2.4 (pages 971-975) regarding their recent summary of cloud feedbacks. They assess the overall cloud feedback as positive with high confidence, but assess the high tropical cloud component as negative with low confidence. In particular the discussion on Page 972 refers to a "stability iris effect" proposed by Bony et.al. (2016 and 2020) and supported by recent CRM simulations. Perhaps by digging further one might find it to be inspired in some way by Lindzen's original hypothesis? In any case, I wouldn't knock myself out trying to clear the whole thing up if the IPCC assessment is presently at low confidence. Bikesrcool (talk) 20:08, 19 December 2023 (UTC)

Hi Bikesrcool, I checked this again with Kevin Trenberth and here is his reply (so it's not related to Lindzen's hyphethis): "There are many ongoing issues about how clouds change with climate change and AR6 may not have it right either. But this has nothing to do with the iris hypothesis. "Iris" may be mentioned as a blocking or lack of blocking (opening iris) of LW radiation but this really has nothing to do with Lindzen's hypothesis. The reason why this may be all wrong anyway relates to local vs remote influences. In El Nino, warming SSTs in eastern tropical Pacific burn off low level Stratocumulus and so the warm SSTs warm even more. But at the same time there are large-scale dynamics occurring: changes in the Walker Circulation. The results for tropical eastern Pacific likely do not apply generally, but have been interpreted that way in some misleading studies." EMsmile (talk) 13:48, 20 December 2023 (UTC)

Thank you and Kevin. I'm not well read on this dense topic. Reply suggests that the cited sources for "iris effects" referenced at the end of this article and the "fixed anvil temperature hypothesis" article might also have little or "nothing to do" with Lindzen's hypothesis... aside from similar superficial features. It's a useful note of caution for editors going forward. Bikesrcool (talk) 16:44, 22 December 2023 (UTC)