Paper finds a decrease of IR radiation from greenhouse gases over past 14 years, contradicts expected increase – cloudiness blamed for difference.
A paper published in the Journal of Climate finds from 800,000 observations a significant decrease in longwave infrared radiation from increasing greenhouse gases over the 14 year period 1996-2010 in the US Great Plains. CO2 levels increased ~7% over this period and according to AGW theory, downwelling IR should have instead increased over this period.
According to the authors,
“The AERI data record demonstrates that the downwelling infrared radiance is decreasing over this 14-yr period in the winter, summer, and autumn seasons but it is increasing in the spring; these trends are statistically significant and are primarily due to long-term change in the cloudiness above the site.”
The findings contradict the main tenet of AGW theory which states increasing greenhouse gases including the primary greenhouse gas water vapor and clouds will cause an increase of downwelling longwave infrared “back-radiation.”
The paper also finds a negative trend in precipitable water vapor, as do other global datasets, again the opposite of predictions of AGW theory that warming allegedly from CO2 will increase precipitable water vapor in the atmosphere to allegedly amplify warming by 3-5 times. Is the unexpected decrease in water vapor the cause of the decrease in downwelling IR?
Global datasets also show an increase of outgoing longwave IR radiation to space from greenhouse gases over the past 62 years, again in contradiction to the predictions of AGW theory.
Gero, P. Jonathan, David D. Turner, 2011: Long-Term Trends in Downwelling Spectral Infrared Radiance over the U.S. Southern Great Plains. J. Climate, 24, 4831–4843.
doi: http://dx.doi.org/10.1175/2011JCLI4210.1
Long-Term Trends in Downwelling Spectral Infrared Radiance over the U.S. Southern Great Plains
P. Jonathan Gero
Space Science and Engineering Center, University of Wisconsin—Madison, Madison, Wisconsin
David D. Turner
NOAA/National Severe Storms Laboratory, Norman, Oklahoma, and Department of Atmospheric and Oceanic Sciences, University of Wisconsin—Madison, Madison, Wisconsin
Abstract
A trend analysis was applied to a 14-yr time series of downwelling spectral infrared radiance observations from the Atmospheric Emitted Radiance Interferometer (AERI) located at the Atmospheric Radiation Measurement Program (ARM) site in the U.S. Southern Great Plains. The highly accurate calibration of the AERI instrument, performed every 10 min, ensures that any statistically significant trend in the observed data over this time can be attributed to changes in the atmospheric properties and composition, and not to changes in the sensitivity or responsivity of the instrument. The measured infrared spectra, numbering more than 800 000, were classified as clear-sky, thin cloud, and thick cloud scenes using a neural network method. The AERI data record demonstrates that the downwelling infrared radiance is decreasing over this 14-yr period in the winter, summer, and autumn seasons but it is increasing in the spring; these trends are statistically significant and are primarily due to long-term change in the cloudiness above the site. The AERI data also show many statistically significant trends on annual, seasonal, and diurnal time scales, with different trend signatures identified in the separate scene classifications. Given the decadal time span of the dataset, effects from natural variability should be considered in drawing broader conclusions. Nevertheless, this dataset has high value owing to the ability to infer possible mechanisms for any trends from the observations themselves and to test the performance of climate models.
via the Hockeyschtick with thanks
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One site is better than a thousand models – lets get it replicated and see what we get.
It all rested on positive feedback. Poooof! Observations trumps hypothesis (NOT THEORY) every time. Go cry in your cornflakes, it’s nearly over.
Negative feedback. That crappy idea they like to ignore is the reason why we are still here!
Steven Mosher says:
August 5, 2014 at 4:52 pm
One site.
>>>>>>>>>>>>>>>>>>
Did any of the climate models predict this particular regional result? Any?
Presumably regional cloud patterns change as the climate changes, so the study doesn’t appear strong enough to say much about AGW. On the other hand, if the findings were the opposite of those actually made, I’m sure this study would be viewed as a pinnacle of warmist science. 😉
Jimbo says:
August 5, 2014 at 5:17 pm
Without the positive feedback from more water vapor assumed in the GCMs, catastrophic man-made global warming or climate change does indeed go poof! The most its advocates could then hope for would be the ~1 K warming from doubling 280 ppm found in the lab. I suspect that in the real world climate sensitivity would be even less than that and possibly even a cooling in some environments or under certain conditions.
Jimbo says:
August 5, 2014 at 5:17 pm
…
“will cause an increase of downwelling longwave infrared “back-radiation.”
…
Isn’t it true, that a regular old fashioned cloud will block out the longwave infrared emitted from the sun if the cloud happens to get in between the sun and the instrument?
2011, How was this paper addressed in the last IPCC roll up?
” Jimbo says:
August 5, 2014 at 5:17 pm
It all rested on positive feedback. Poooof! Observations trumps hypothesis (NOT THEORY) every time. Go cry in your cornflakes, it’s nearly over.”
You’re really willing to bump it up to hypothesis?
Because, where I stand, it may make it to conjecture. Slapping on an agenda doesn’t move something up the scale.
The paper Alec cites above seems to be in conflict with the headline paper, as it shows a decrease in clouds. I assume that the headline paper is ascribing the decline in IR to an increase in clouds (“long-term change in the cloudiness”), and I’m puzzled that the lead paper also shows a decrease in at least one form of water vapor. This needs untangling, at least for me.
INteresting! This one CAME from WordPress, not WUWT (I get notifications).
I guess this may be the turning point. UP next – Global Cooling from CO2.
The Great Plains are sometimes called the Great American Desert. Desert is relative. Defined by average annual rainfall. And while they do not rival the Atacama, the amount is still relatively low.
So they actually did do it in a desert. Just ask any of the survivors of the dust bowl.
H Grouse says:
August 5, 2014 at 5:25 pm
Depends on the wavelength of the downwelling IR. Some incoming solar IR energies are blocked by clouds & some aren’t.
Is this the same site Mosh? It seems as if this observation was seen before.
I’m just an average guy, is this as important as it seems to me or am I readign into it incorrectly?
To Jimbo , sturgishooper, philjourdan, et. al
…..
“But now they only block the sun
They rain and snow on everyone
So many things I would have done
But clouds got in my way”
(Thank you Joni)
@H Grouse – thank you for sharing the source of your science. She is a great singer. Not so much on the science side however. We do not know if you are a good singer.
philjourdan says:
August 5, 2014 at 5:33 pm
The Great Plains aren’t technically a desert, ie with less than eight inches of precipitation a year. The long grass prairie actually gets quite a lot of rain, hence its abundant unirrigated corn & bean crops. The short grass prairie & high plains get less, but still more than a desert.
The relevant site is in Lamont, OK, with average annual rainfall around 34 inches, maybe more.
I believe I did state that the name is a colloquialism and not an actual scientific designation. And OK is usually not thought of when discussing the “great plains”. The exact definition varies by those using the term.
Nick Stokes says:
August 5, 2014 at 5:01 pm
“……………But it doesn’t contradict any main tenets. It states explicitly that the result is due to a change in cloudiness. And since they measured cloudiness, that is not speculation.”
=============================================================================
You must be kidding I mean this has to be joke, right? Come on Nick, A main tenet of global warming theory is that all or at least the vast majority of Feedbacks are positive. If clouds are a negative feedback then that has smashes a major tenet.
If reduced cloud cover is responsible, then that is what the theory predicts.
Its just that low clouds produce more sunlight reflection/albedo (reduced downwelling solar) than they provide for increased downwelling longwave, so there can still be an increase in overall downwelling radiation with reduced low cloud cover.
Net cloud radiation forcing is -21 W/m2 with about -51 W/m2 reflected solar/albedo versus +30 W/m2 in increased downwelling long-wave.
The theory predicts a change in these numbers of +0.70 W/m2 per 1.0C increase in temperatures (or a change from -21.0 W/m2 to -20.3 W/m2 per 1.0C increase.
Mosh says its just one site. What else could he say? He’s trapped in the corner, there is no way out. He’s a desperate man.
Tom Trevor says:
August 5, 2014 at 5:42 pm
Even more destructive would be a negative feedback from water vapor. By destructive, I mean, totally destroying in detail, smashing, obliterating, annihilating and wiping off the face of the earth, plowing salt into the site of its prior existence, the repeatedly falsified, intentional lie of catastrophic man-made global warming.
Steve Mosher’s cryptic comment “one site” deserves amplification. More sites would be better. In a larger sense, the key dynamics are over the ocean. There are many reasons why the IR response to increased CO2 over oceans would be different.
To summarize:
1. One location
2. The main event is the ocean dynamics
3. Even for land dynamics, the results are difficult to generalize because we cannot model the clouds.
All this said, if the result had gone the other way, it would be trumpeted by alarmists as proof positive of catastrophic climate change. It would not have been. Had the result shown increased down-welling IR, it would only have been a slight confirmation of a point on which most of us agree. increased CO2 has an impact on IR.
Moshey bOy – Only takes one negative case to disprove a hypothesis
davidmhoffer says: August 5, 2014 at 5:23 pm
“Did any of the climate models predict this particular regional result? Any?”
The paper attributes the reduction primarily to cloud reduction, and the drop in clear-sky radiance to a reduction in humidity. And yes, the AR4 projects reduced precipitation for Oklahoma.
REPLY: Precipitation is not the same as precipitable water vapor Nick. Models suggest an increase in water vapor. – Anthony
Seems to me this finding takes us back to where I began in all this many years ago, to the fairly old “sunspot – solar wind – cosmic ray – cloud formation” theory. As the theory goes: Fewer sunspots equals less solar wind equals more cosmic rays equals more cloud cover equals cooler temperatures. I would have thought the CERN bubble chamber experimental outcome would have maintained focus on this theory. So why is any of this “new news”?