Roy Spencer's paper on climate sensitivity
What the science says...
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Spencer's model is too simple, excluding important factors like ocean dynamics and treats cloud feedbacks as forcings. |
Climate Myth...
Roy Spencer finds negative feedback
"NASA satellite data from the years 2000 through 2011 show the Earth's atmosphere is allowing far more heat to be released into space than alarmist computer models have predicted, reports a new study in the peer-reviewed science journal Remote Sensing. The study indicates far less future global warming will occur than United Nations computer models have predicted, and supports prior studies indicating increases in atmospheric carbon dioxide trap far less heat than alarmists have claimed." (James Taylor)
Climate scientists have identified a number of fundamental problems in Spencer and Braswell's 2011 study which wrongly concludes that the climate is not sensitive to human greenhouse gas emissions. One of the main problems with the paper is that it uses Roy Spencer's very simple climate model which we've previously looked at in .
This simple model does not have a realistic representation of the Earth's oceans, which are a key factor in the planet's climate, and it also doesn't model the Earth's water cycle. One key aspect in the Earth's temperature changes is the El Niño Southern Oscillation (ENSO), which is a cycle of the Pacific Ocean. Spencer's model does not include ENSO, and he assumes that ENSO responds to changes in cloud cover, when in reality it's the other way around.
There are some other key problems in the paper. It doesn't provide enough information for other scientists to repeat the study. When two other climate scientists (Kevin Trenberth and John Fasullo) tried to replicate its results as best they could with the information provided, they found quite different results (see the Advanced version of this rebuttal for further details). Spencer and Braswell's conclusions also only seems to work using the satellite data set they chose, but Trenberth and Fasullo found that using other data sets also changes their results.
Trenberth and Fasullo also found that when using a few different climate models, the one which replicated the observed data best was the one with a climate more sensitive to greenhouse gases, which directly contradicts Spencer and Braswell's conclusion that the climate is not sensitive to greenhouse gases.
It's also worth noting that the journal which published Spencer and Braswell's paper does not normally publish climate science research. This may explain how the paper made it through their peer-review system with so many problems. In the end, Trenberth and Fasullo find that the Spencer and Braswell study has no merit.
- The model it uses is far too simple to accurately represent the Earth's climate
- The paper doesn't provide enough information to replicate their results
- Their results depend on using one particular data set
- They assume that ENSO responds to cloud cover changes, when in reality, the reverse is true
- The study's conclusions are incorrect and unsupportable
UPDATE 3 Sep 2011: Wolfgang Wagner, has stepped down as editor-in-chief of the journal Remote Sensing. Wagner concluded the Spencer's paper was "fundamentally flawed and therefore wrongly accepted by the journal". More here...
Last updated on 1 August 2011 by dana1981.
[DB] "I am trying to quit, if the moderator will allow me the courtesy of exiting gracefully and not appearing to be slinking off into the shadows. Pretty please?"
Moderator baiting is not an endearing trait in any venue; desist.
If you cannot handle the hard questions from knowledgeable persons then you should not posit what amounts to curve-fitting mathturbation/climastrology. From the inception of your comments on this thread you have offered up nothing of substance to support your assertions.
Like Spencer, you serve up vacuous handwaving, smoke, mirrors and blustrous intimations of conspiracy to suppress the New Truth. You follow that up with failed, disingenuous threats of running away from requests for answers. Run then.
Just stop wasting everyone's time.
I have read the comments posted here and have a few of my own to make.
1) There is a great desire to discredit Spencer as a junk scientist. Allow me to advance the following argument. Even though the elitism of Science and its direct disconnect from the majority of the people on this planet has resulted in a large number of geniuses playing with mathematical models largely irrelevant to daily existence, the impact of guesswork is not minute. The entire exercise witnessed here strikes me as the pot calling the kettle black. Climate modeling is a political issue. No, it is not a Scientific issue, because it is not Scientific. Science relies upon direct observation – not extrapolation. Empiricism underpins Science. Modeling is an aid to Science. Theory is not Science. At best a theory is a guess at the consistency of Reality. Climate modeling is an exercise in Mathematics. Models are based on assumptions. Assumptions prove nothing.
2) Geology as an empirical Science has demonstrated a long term trend in global climate. On average, every 100,000 years temperature peaks accompanied with a high in CO2 levels. Yet, the relationship is not consistent, nor does it explain the effect of shorter cycles - more precisly our current placement within all the cycles: long, medium, and short.
Milankovitch in brief: http://ossfoundation.us/projects/environment/global-warming/milankovitch-cycles
CO2 and temperature trend not directionally consistent: http://joannenova.com.au/global-warming-2/ice-core-graph/
Shorter cycles have an impact: http://www.ncpa.org/pub/st279?pg=13
3) The dominant opinion in Climate Science appears to ignore the above, or to acknowledge this with qualification. The most worrying element in this is the propaganda: human activities are causing climate change. Causality. If, at this moment you are not slightly uncomfortable, you might be practicing in the wrong field. [At the same time the statement can be so ambiguous as to allow the bigot to claim correlation.]
4) I have a number of questions regarding climate modeling:
a. How is “human activity” operationalized? In research, concepts have to be measurable. Data has to be obtained. That data must be accurate, valid, and reliable. It would appear that in Climate Science that this concept is largely imputed.
b. What dataset used in Climate Science dates back more than 100 years (do recall the long term cycle of 100,000 years) and:
i. Is continuous,
ii. Measured consistently (across the globe, using the same methodology), and
iii. Applied without extrapolation.
5) As a suggestion this question may be relevant: if there is a natural long term trend, what impact does human behavior have on raising global temperature above the natural trend? Please explain to me how you will answer this question. Even propose an alternative to it if you must.
[RH] This post probably should be deleted for a multitude of reasons. But since several regular commenters seem eager to engage we'll let it stand as is.
Deon... Before continuing to post, you need to read the commenting policy document that is linked right above the text box. Please, try to stay on topic and keep your individual points limited to the appropriate threads. Discussing the science is a healthy thing. We just require that you follow certain rules in order to keep the discussions productive.
Deon, I hope you'll continue to engage, but on the appropriate threads. The answers you seek are on this site, all linked to the published science. Use the search feature. I could make a series of links to the appropriate threads, but you've galloped so wide and far that I'd basically have to link the entire site.
Deon you make broad statements that indicate only your lack of true familiarity with the body of knowledge you pretend to criticize. There is plenty of information available here and links to NASA, NOAA and yoher sites, where an abundance of data is available. Assessment reports of the IPCC are also recommended reading.