The lower troposphere represents that layer of the atmosphere which is predicted to first experience the positive feedback of accelerated warming due to human greenhouse gases.
Recently, NOAA and NASA held a global warming presentation, which included various charts, and an unexpected admission that the atmosphere was not as warm as previous El Niño years.
An essential general review of the presentation can be found here.
The troposphere's lack of achieving the "warmest" year label was confirmed by the NOAA/NASA analysis of the relevant balloon and satellite datasets. And the adjacent chart is a combination from the NOAA/NASA presentation, with one chart being superimposed atop the other.
Other than a normal atmospheric response to the latest large El Niño temperature surge, the chart documents the continued lack of dangerous positive feedback warming.
"Consensus" scientists have responded by producing multiple speculative reasons as to why the disappearance of global warming has occurred, without any convincing success.
In contrast, objective researchers have chosen to reexamine the actual empirical measurement evidence to determine if the "consensus" estimate was realistic, and if not, what a more accurate estimate would be for climate sensitivity.
As this article describes, new scientific studies have recently been published, strongly indicating that both a long-term and short-term sensitivities are significantly lower than the failed assumptions of the IPCC.
The new research, depending on the time-frame chosen, indicates empirically-based climate sensitivity ranging from +1.0°C to +2.9°C.
Using the above 'C3' tool to estimate different global warming outcomes dependent of climate sensitivity chosen, it can be determined that if this century's climate sensitivity is closer to the '+1.5' the new studies suggest, then the global temperature impact would be a very modest +0.52°C - clearly, not the over-the-top +6 or more degree possibilities tossed about by many "consensus" scientists.
Note: To use the 'C3' global temperature estimator, click on the above image. Input your preferred variable data into the yellow boxes and press 'Enter' or 'Tab' key. Additional 'C3' tools.
IPCC scientists assume that human CO2 emissions will continue to accumulate in the atmosphere, remaining anywhere from hundreds to thousands of years.
This assumption is a cornerstone of the AGW hypothesis. The cumulative CO2 growth causes global warming that accelerates (they hypothesize) to a condition of "runaway" temperature increases via positive feedbacks, leading to catastrophic "tipping point" climate change.
To simplify, the CO2-centric AGW hypothesis, and climate models, assume that every additional emission molecule of atmospheric CO2 will accelerate the global warming, to the point of no return. Thus, each new tonne (metric) of CO2 will boost the acceleration via a theoretical positive feedback amplification.
But does the empirical evidence actually indicate that is indeed what is taking place?
Using a combination of the NOAA annual global temperature dataset and two sources of global CO2 emissions from fossil fuels, it can be determined how each new tonne of CO2 emissions is "accelerating" temperatures, or not.
This article's chart provides the answer. As can be observed, each new CO2 emission molecule added to the climate has a smaller and small impact, the opposite of the AGW hypothesis. In 1941, the degree increase per tonne hit a peak. Since then, the impact of each tonne has decreased, significantly - currently it stands at +0.00000000000021°C/tonne.
The AGW hypothesis does not account for this ever smaller impact of CO2. Possibly this is the reason for the "consensus" unexpected global warming 'hiatus', which the IPCC scientists are still at a loss to explain.
If this tiny impact stays constant over the next 30 years, and the growth rate of CO2 emissions over the last 15 years remains the same for the next 30 years (another trillion tonnes emitted), the potential increase of global temperatures will barely be +0.2°C (two-tenths of a degree) by year 2044. And if each tonne's impact continues to shrink, as the evidence suggests, so will the temperature increase shrink.
Now, adding to this miserably low warming influence of CO2 is the recent admission by establishment climate science that natural climatic forces have a powerful say in the trend of global temperatures, regardless of human CO2 emissions. As the Nature science journal indicates, currently, and for the near future, a natural PDO cooling phase may dominate.
More on the above 'C3' chart. Specifically, it plots a ratio of 30-year NOAA temperature changes to the cumulative amount of CO2 tonnes emitted up to that point. For example, the 1941 ratio has a numerator of +0.59°C (30-year annual temperature change) and a denominator of 165 billion CO2 tonnes (the cumulative amount emitted from 1880 through 1941). This ratio calculation is made for each year, starting with 1910 (30 years after 1880).
The ratio allows for depicting visually the influence of all those previous CO2 emissions on moving 30-year climate periods. The chart's additional green and light blue curves simply provide a smoothed sense of direction of the fossil fuel emission influence.
Summary: The observed shrinking of CO2's influence on global warming does not bode well for the future longevity of the AGW hypothesis. Per the well known and documented CO2 physics, this outcome should not be a surprise. It's just another case of 'those stubborn facts' in science.
The IPCC's catastrophic AGW (CAGW) hypothesis is based on the prediction that human CO2 emissions would produce a "hotspot" in the atmosphere above the tropics. This hotspot was identified by the IPCC as the penultimate evidence that global warming was accelerating, causing a "tipping point" cascade of catastrophic events.
The projected hotspot over the tropics was expected to stretch from the 5km mark to as high as 15km, with the hottest portion being from 8-12km. The temperatures in this specific area were supposed to rise 1.2 to 1.5 times faster than surface temperatures, due to positive feedback loop produced by the CO2-induced warming.
Big problem though. As this chart of the lower troposphere (over the tropic latitudes) documents, NASA satellites are unable to locate this mysterious, runaway "hotspot" (AGW "signature" and/or "fingerprint") that the IPCC and global warming alarmists have long predicted. This despite NASA satellites having 100% coverage over the entire tropical troposphere, including the critical water vapor areas of the lower and mid-troposphere.
In fact, this specific area of the troposphere has only warmed a fraction of the IPCC's predictions, turning the "hotspot" into the embarrassing "AWOLspot." Additionally, this means that the feared AGW positive feedback loop went kaput, or it never really existed, except in the "consensus" hive mind of the alarmist-science collective.
Additional chart info: the red-dotted curve is a basic 36-month moving average; the green curve is 6th order fitted trend of monthly measurements; and the grey area represents the cumulative per cent growth of atmospheric CO2 levels. (Since satellite monitoring of atmospheric temperatures began, the cumulative growth of CO2 ppm levels has been over 18%.)
Per this satellite empirical evidence, the existing linear temperature trend of the low-troposphere tropic latitudes is ludicrously small, indicating that 2100AD temperatures may only increase by +0.6°C (necessary warning: trends are not predictions, don't go there). For the mid-troposphere tropics, the trend is even lower, +0.3°C. Compare those low trend rates with the modest warming trend of the entire atmosphere: +1.2°C by 2100AD.
And the comparison to the surface temps? NASA/GISS has a linear trend for the same time period projecting an outcome of +1.3°C by 2100AD.
Yep, you read that correctly. The tropical hotspot trends are lower than the global atmospheric trend and the global surface trend - a magnificent and spectacular fail of IPCC climate "science."
The simple, indisputable, scientific summary after 35 years of empirical evidence: The tropical, runaway hotspot did not happen in spite of massive amounts of CO2 emissions released into the atmosphere; ergo, the IPCC was wrong, again; the billion-dollar climate model predictions were wrong, again; alarmist, agenda-driven scientists' claims of climate doomsday were wrong, again; and, the fanatical anti-CO2 green lobby was wrong, as always.
Note: Links to datasets used in Excel to create chart: UAH satellite & NOAA CO2. Don't know how to chart in Excel? It's easy. Go here to learn how.
The ultimate test for the IPCC's catastrophic AGW hypothesis is the existence of the predicted "hotspot" that is a sign of a positive feedback loop for accelerating global warming - newest data show that even after record setting human CO2 emissions the "hotspot" failed to materialize
Per the IPCC's global warming hypothesis, at the very top of the troposphere, above the equator region, is the location (12km, 200hPa @ 20°N - 20°S) that triggers a positive climate feedback, which produces the mythical runaway, tipping point of accelerated, dangerous global warming, which of course is unequivocal and irrefutable, except when it isn't.
This location is often referred to as the tropical "hotspot," supposedly an artifact of modern industrial/consumer human CO2 emissions.
The high climate sensitivity programmed into the IPCC's climate models is entirely dependent of this hotspot of positive feedback - with the hotspot, climate models predict a scary global warming range that spans from 2°C to 6°C.
If there is no tropical upper troposphere hotspot, then there is no positive feedback, and thus, no climate change crisis as predicted by the IPCC. If there is no hotspot, then the IPCC hypothesis of CO2 caused global warming (AGW) is essentially proven false.
Based on accepted physics, without the positive feedback triggered by the hotspot, surface global temperatures from a doubling of pre-industrial CO2 will increase by some +0.5° to 1.5°C. That is the range climate models predict (depending on the given climate model) if the "hotspot" does not exist.
The IPCC's gold-standard for upper troposphere data is the UK's HadAT2 dataset that represents high altitude balloon/radiosonde measurements. These balloons provide a higher resolution of the atmospheric layer temperatures than current satellites can provide. Over time, approximately 28+ million radiosonde measurements have taken place.
A few days ago (2/19/2013), the HadAT2 was finally updated through December 31, 2012 - the previous update of dataset was through 12/31/2011. The above chart plots the latest AT2 dataset and concurrent, well-mixed atmospheric CO2 levels over the last 17 years. (Why 17?)
Conclusions from the chart:
#1.The IPCC's tropical "hotspot" does not exist.
#2. Atmospheric CO2 levels over 350ppm do not cause a hotspot to occur.
#3. The climate sensitivity to CO2 is lower than expert assumptions.
#4. Temporary natural El Nino events do cause a spike in upper troposphere temperatures but then return to a lower temperature state (no positive feedback loop).
#5. The IPCC, its experts and climate models have been wrong about the mythical hotspot since the UN created the IPCC (1988).
#6. The continuing abysmal failure of climate models is likely associated with the lack of the mythical, hypothesized hotspot.
#7. The AGW hypothesis of tipping point, climate positive feedback is proven false after decades of zero empirical evidence supporting it.
#8. Despite all empirical evidence, IPCC scientists and bureaucrats will keep pushing the hotspot, positive feedback hypothesis in order to continue their lucrative taxpayer funding.
Recently, a new 2012 study by Stephen Po-Chedley and Qiang Fu found:
"It is demonstrated that even with historical SSTs as a boundary
condition, most atmospheric models exhibit excessive tropical upper
tropospheric warming relative to the lower-middle troposphere as
compared with satellite-borne microwave sounding unit measurements. It
is also shown that the results from CMIP5 coupled atmosphere–ocean GCMs
are similar to findings from CMIP3 coupled GCMs. The apparent
model-observational difference for tropical upper tropospheric warming
represents an important problem..."
Previous studies have documented the tropical hotspot problem (source for all quotes here):
"Climate models and theoretical expectations have predicted that the
upper troposphere should be warming faster than the surface.
Surprisingly, direct temperature observations from radiosonde and
satellite data have often not shown this expected trend." Sherwood et al 2008.
"On multi-decadal timescales, tropospheric amplification of surface
warming is a robust feature of model simulations, but occurs in only one
observational dataset." Other observations show weak or even negative amplification.” Santer et al 2005
“A recent report of the U.S. Climate Change Science Program (CCSP) identified a ‘potentially serious inconsistency’ between modelled and observed trends in tropical lapse rates.” Santer et al 2008
“Model results and observed temperature
trends are in disagreement in most of the tropical troposphere, being
separated by more than twice the uncertainty of the model mean. In
layers near 5 km, the modelled trend is 100 to 300% higher than
observed, and, above 8 km, modelled and observed trends have opposite signs.” Douglass et al 2007
Update, per a reader's email: First, from the 2nd order draft of the IPCC's AR5, and second, from a comment at Judith Curry's 'Climate Etc.' blog:
"Section 22.214.171.124.2, p. 9-26, lines 31-33: "In Summary, there is a high confidence (robust evidence although only medium agreement) that most, though not all, CMIP3 and CMIP5 models overestimate the warming trend in the tropical troposphere during the satellite period 197902011. The cause of this bias remains elusive.""
"However my working hypothesis is that Santer would have continued to ignore these demonstrations, were it not for the Fu (2011, GRL) paper, which included Syukuro Manabe (godfather of CO2-climate modeling) as co-author also showing disagreement between models and measured temperatures...However, once the Fu 2011 paper came out, it became “establishment” that there was in fact a significant disagreement between models and measured temps. So now after the Fu 2011 paper we have (Thorne, 2011 [JGR], Po-Chedley (2012), Seidel (2012) and Santer (2012) all agreeing that models and measurements for tropical troposphere temperaures cannot be reconciled."
Note 1: A simple
hotspot explanation summarized from this article: Increasing CO2 levels causes atmosphere to warm;
then atmosphere causes Earth's surface to warm; warming of oceans cause
evaporation; increased evaporation leads to more water vapor in the
upper troposphere; water vapor is a powerful greenhouse gas that warms
the atmosphere even more (positive water vapor feedback); the Earth's surface warms
even more; and then auto 'repeat and rinse' until Earth's oceans boil, per an "expert."
Note 2: A scientist discusses the IPCC hotspot issue and dismantles a lame pro-hotspot argument (geesh, talk about alarmists' "scientific" mis-truths).
Note 3: The catastrophic global warming alarmists, be they "scientists" or political hacks, are very alarmed that the "hotspot" never materialized. To cover up this major failure of the AGW hypothesis, they usually attempt excited hand-waving to distract the gullible, including: the disingenuous, circular logic claim that it must exist because the models predict it, thus the measurements must be wrong; or the amazing claim that the hotspot exists but it just doesn't reveal itself to humans (really, trust us, it's hiding).
AGW alarmist climate scientists predicted that increasing human CO2 emissions would cause an increase in water vapor with the result being a global warming tipping point - empirical evidence completely discredits that prediction
(click image to enlarge)
Read here. Very simply, for the IPCC's climate models predicted runway global warming to happen, there has to be a positive feedback from atmospheric CO2 that pushes the climate to a "tipping point." The positive feedback in the IPCC's computer models is an ever increasing atmospheric water vapor level (greenhouse gas) due to rising temperatures from CO2.
In the real world though, that positive feedback has not happened, as the adjacent chart of relative humidity (atmospheric water vapor) and global temperatures shows. And now, a new peer reviewed study in the prestigious Journal of Climate is confirming that the global warming tipping point hypothesis is without any empirical merit.
"A paper published today in the Journal of Climate finds that relative humidity has been decreasing 0.5% per decade across North America during the 62 year period of observations from 1948-2010. Computer models of AGW show positive feedback from water vapor by incorrectly assuming that relative humidity remains constant with warming while specific humidity increases....."Over 1/4 billion hourly values of temperature and relative humidity observed at 309 stations located across North America during 1948-2010 were studied...The averages of these seasonal trends are 0.20 C/decade and 0.07 hPa/decade which correspond to a specific humidity increase of 0.04 g/kg per decade and a relative humidity reduction of 0.5%/decade."" [V. Isaac and W. A. van Wijngaarden 2012: Journal of Climate]
Conclusion: The IPCC alarmist global warming tipping point does not exist over the long term - instead, over periods less than a decade, the climate will likely return to an equilibrium position due to built-in negative feedbacks.
The runaway global warming scenarios of the IPCC climate models are based exclusively on a hypothesized positive climate feedback - satellite data reveal a powerful negative cloud feedback instead
Read here. The IPCC claims of a positive feedback mechanism that would cause runaway global warming, and a climate change tipping point, have never been validated as being climate science reality. Yet the IPCC's climate models all employ this phantom positive feedback, resulting in their infamous predictions of catastrophic climate events.
Unfortunately for the IPCC, its "consensus" climate models are all wrong regarding positive feedbacks. Instead, the latest satellite empirical evidence points to a significant negative cloud feedback that is the likely cause of the lack of global warming over the last 15 years.
"A new paper just published in Geophysical Research Letters by Roger Davies and Mathew Molloy of the University of Auckland finds that over the past decade the global average effective cloud height has declined and that “If sustained, such a decrease would indicate a significant measure of negative cloud feedback to global warming.”...The average global cloud height is linked to the average global temperature—generally, the higher the average cloud height, the higher the average surface temperature, and vice versa...A point well-recognized by Davies and Molloy when they write “Changes in cloud properties in response to rising surface temperatures represent some of the strongest, yet least understood, feedback processes in the climate system.“..."If sustained, such a decrease would indicate a significant measure of negative cloud feedback to global warming, as lower cloud heights reduce the effective altitude of emission of radiation to space with a corresponding cooling effect on equilibrium surface temperature."...According to the calculations of Davies and Molloy, the negative climate forcing from a decrease in the average global cloud amount during the past 10 years has more than offset the positive forcing from an increase in greenhouse gases from human activities." [Roger Davies, Mathew Molloy 2012: Geophysical Research Letters]
Global warming theorists now claim that Arctic sea ice melt causes colder and snowier winters - the empirical evidence indicates that it must also cause colder oceans, a definite AGW negative feedback
(click on images to enlarge)
These Bob Tisdale charts of ocean temperatures through January 2012 are most enlightening. To summarize the data plotted on the charts, ocean temperatures, as represented by the Southern, South Pacific and global measurements, clearly show a decline since the 1998 El Niño event. The Southern Ocean (aka the Antarctica Ocean) has experienced a very significant decline in temperature since the early 2000's.
Sooo...per the logic of the typical global warming alarmist, the Arctic sea ice melt from human CO2 emissions does the following, from one Polar region to its geographic opposite:
In essence, the tortured logic of the ever-changing alarmist climate change theories literally leads one to conclude that global cooling weather events are the natural negative feedback to AGW.
Of course, no IPCC climate change report (so far) has remotely stated the above. But the actual climate empirical evidence (ie, non-warming world, lower ocean temps) and cold weather events has now forced CO2-centric global warming alarmists into a pretzeled logic that ultimately supports the overall negative feedbacks of global climate as understood by CAGW-skeptics, not the positive feedbacks pushed by the IPCC.
IPCC alarmists and climate models predicted that global warming of peatlands would initiate a positive feedback resulting in the increase of CO2 emissions - conclusive research finds the polar-opposite
Read here. Like almost every single predicted positive feedback by the IPCC's Climategate scientists and models, the actual empirical evidence finds that nature abhors positive feedbacks. The warming of peatland (peat bogs) is no different.
[Note: Click on the image, then read the 2nd paragraph to see an example of how the failed climate science predictions of the IPCC corrupts common knowledge.]
Objective, non-activist scientists researched the IPCC peatland prediction and discovered that instead of being a positive feedback, peat regions would be a negative feedback during warming climates.
"Global warming is often predicted to lead to the releasing to the atmosphere of long-sequestered carbon in earth's peatlands, possibly freeing enough of it at a sufficiently rapid rate to rival CO2 emissions from anthropogenic sources, with the end result of this scenario being a strong positive feedback to the ongoing rise in the air's CO2 content, which climate alarmists contend will lead to further warming of the planet...employed multi-proxy data derived from a 1073-cm sediment core they extracted in March of 2007 from Tannersville Bog...in order to document the Bog's historical peat accumulation pattern and rate, as well as climate variations experienced by this "temperate tree-covered poor fen"...say their study implies that "northern peatlands can continue to serve as carbon sinks under a warmer and wetter climate, providing a negative feedback to climate warming," which is the exact polar-opposite of what has historically been claimed by the world's climate alarmists." [Shanshan Cai,Zicheng Yu 2011: Quaternary Research]
IPCC "experts" and climate models predicted that CO2 increases would cause runaway growth in atmospheric water vapor & temperatures - wrong on both counts
As the adjacent chart shows, atmospheric CO2 levels have been methodically rising. Per the IPCC's climate models and its Climategate experts, the rising CO2 should cause a water vapor "tipping point" that would cause "runaway" warming. It hasn't, on both counts.
The bold blue curve reveals atmospheric relative humidity actually decreasing (less water vapor) over the last 17 years since the end of 1994. The bold red curve represents the slowing growth of atmospheric warming, as measured by NASA's own satellite.
In essence, the fabled positive feedback the climate models use does not exist, and climate sensitivity to CO2 levels is robustly lower than assumed.
If the 17-year satellite linear trend were to continue unchanged, the global temperature increase by year 2100 would be only +1.13 degrees, well below the IPCC's minimum prediction. The last 10-year linear trend (not shown in chart) indicates an increase of a measly +0.3 degrees for global temps by 2100, which would be barely perceptible.
Simply stated, the IPCC can't predict squat, especially anything to do with climate changes due to human CO2. Establishment science and coastal elites are literally besides themselves as the empirical evidence continues to affirm that the "consensus" IPCC catastrophic AGW hypothesis is at best, lame, and more likely just plain invalid.
Read here. It is well documented that the IPCC's climate "experts" (software programmers) inserted a very high (unproven) CO2 climate sensitivity into the computer climate models. For PR propaganda purposes, the IPCC's climate simulations then foretold a future climate of potentially high temperatures due to the mysterious "tipping point."
As this typical climate model prediction chart reveals though, there is an obvious real-time problem with the IPCC programmers' assumption that the climate is highly sensitive to high levels of atmospheric CO2.
New peer-reviewed research has found that the IPCC's climate models are wrong, and the prediction of "accelerating" global warming due high climate sensitivity is wrong. The research confirms previousstudiesthat the projected future tipping point climate conditions were falsehoods. The actual science again proves global warming skeptics to be correct and, more robustly, that anti-science global warming alarmists, such as Chris Mooney, to be...well...er...pathological liars, exaggerators hysteria-loving alarmists who ignore climate reality.
Much to the major chagrin of climate alarmists everywhere, the Schmittner et al. team conclude that an approximate global temperature increase of 2.5 degrees is a much more likely outcome than the over-inflated 5.0 degrees publicized by the IPCC. This new finding makes the upcoming IPCC's the-world-is-melting convention in Durban, South Africa the penultimate farce.
"There is word circulating that a paper soon to appear in Science magazine concludes that the climate sensitivity—how much the earth’s average temperature will rise as a result of a doubling of the atmospheric concentration of carbon dioxide—likely (that is, with a 66% probability) lies in the range 1.7°C to 2.6°C, with a median value of 2.3°C....In the new paper, the authors find only “vanishing probabilities” for a climate sensitivity value greater than 3.2°C and that values greater than 6.0°C are “implausible.”...results join a growing number of papers published in recent years which, by employing investigations of the earth’s paleoclimate behavior (that is, how the earth’s temperature changes in the past when subject to changing climate forcings) have come to somewhat similar conclusions..." [Schmittner, A., et al., 2011: Science]
Read here. Climate scientist Andy Dessler produced research that was a supposed refutation of the Spencer and Braswell research. It was pointed out previously that Dessler chose not to use the same HadCRUT data as Spencer, which smacks one as an extreme form of cherry-picking.
If one is to challenge another scientist's research, should they not be held to the standard of using the same data to make their case? Well....apparently not in Dessler's case since he obviously is driven by a political agenda, not a scientific one.
So, what happens when the Dessler methodology uses the gold-standard HadCRUT data that Spencer used? As Steve McIntyre discovers, the new results actually resemble Spencer's output suggesting that clouds provide a negative feedback.
Well, everyone now knows why Dessler avoided the HadCRUT data. His refutation of the Spencer study was literally a sham.
"Having exactly replicated Dessler’s regression results and Figure 2a, I’ve repeated the exercise with CERES clear sky in combination with CERES all sky, and with the widely used HadCRUT3 series and got surprising results...The supposed relationship between CLD forcing and temperature is reversed: the slope is -0.96 w/m2/K rather than 0.54 (and with somewhat higher though still low significance)."
Read here. (h/t Australian Climate Madness) NASA's satellite technology and climate science experts deliver the conclusive evidence: climate models are wrong (again!) in regards to atmospheric warming. The satellite evidence reveals that the atmosphere is many times greater at releasing energy to space than the IPCC climate models assumed.
This new peer-reviewed research presents a highly probable reason for why the globe has not warmed anywhere near the predictions of the IPCC Climategate scientists. Simply put, if atmospheric warming is significantly less than predicted, then surface warming will be correspondingly less as a result.
"Data from NASA’s Terra satellite shows that when the climate warms, Earth’s atmosphere is apparently more efficient at releasing energy to space than models used to forecast climate change have been programmed to “believe.”...The result is climate forecasts that are warming substantially faster than the atmosphere...compared what a half dozen climate models say the atmosphere should do to satellite data showing what the atmosphere actually did during the 18 months before and after warming events between 2000 and 2011...“The satellite observations suggest there is much more energy lost to space during and after warming than the climate models show,”...“There is a huge discrepancy between the data and the forecasts that is especially big over the oceans.” [Roy W. Spencer, William D. Braswell 2011: Remote Sensing]
Read here. Recently, NASA's James Hansen rounded up some exceptionally gullible and dim-witted teenagers to do legal battle for him in court. Hansen speculates that human CO2 increases will raise global temperatures so much that positive feedbacks occur causing a runaway global warming "tipping point."
Unfortunately for the dumb ass teenagers and their legal team, new peer-reviewed research (Barreiro et al.) determines that greater warming invokes a climatic tropical cloud negative feedback, not a positive feedback. This climate model research outcome basically eviscerates not only Hansen's speculative "tipping point" hypothesis, but also the teenagers' anti-science legal case crusade, pushed on them by a group of hysterical, manipulative adults.
"Using an atmospheric general circulation model coupled to a slab ocean we study the effect of ocean heat transport (OHT) on climate...results indicate that the climate warms only if the OHT increase does not exceed more than 10% of the present-day value in the case of a strong cloud-SST feedback and more than 25% when this feedback is weak. Larger OHT increases lead to a cold state where low clouds cover most of the deep tropics increasing the tropical albedo and drying the atmosphere. This suggests that the present-day climate is close to a state where the OHT maximizes its warming effect on climate and pose doubts about the possibility that greater OHT in the past may have induced significantly warmer climates than that of today." [Marcelo Barreiro, Simona Masina 2011: Journal of Climate]
Read here. The essential foundation of the AGW hypothesis is that CO2 atmospheric increases block the escape of infrared radiation and increasingly bounces the infrared warming back to the Earth's surface to warm it. But when examining the empirical evidence, the infrared radiation bouncing back to Earth is mostly decreasing, not increasing. This is a likely the explanation for the disappearing global warming over the last 15 years.
Simply put, this is the exact opposite of what IPCC climate models and its faux climate scientists predicted.
Researchers Gero and Turner, using highly accurate technology, measured the decreases of infrared radiation reaching the surface and contend the decrease is due to increased cloudiness over the site - that's called a negative feedback, which Dr. Roy Spencer has presciently espoused.
"A study published online yesterday in The Journal of Climate, however, finds that contrary to the global warming theory, infrared 'back-radiation' from greenhouse gases has declined over the past 14 years in the US Southern Great Plains in winter, summer, and autumn. If the anthropogenic global warming theory was correct, the infrared 'back-radiation' should have instead increased year-round over the past 14 years along with the steady rise in atmospheric carbon dioxide"......"A trend analysis was applied to a 14-year time series of downwelling spectral infrared radiance observations from the Atmospheric Emitted Radiance Interferometer (AERI)...The AERI data record demonstrates that the downwelling infrared radiance is decreasing over this 14-year time period in the winter, summer, and autumn seasons but is increasing in the spring; these trends are statistically significant and are primarily due to long-term change in the cloudiness above the site." [P. Jonathan Gero and David D. Turner 2011: Journal of Climate]
Read here. IPCC Climategate science predicts that as CO2 increase in atmosphere, the resulting warming will increase the atmosphere's water vapor levels, which will cause more warming (a positive feedback).
Unfortunately for the IPCC, that major tenet of the AGW hypothesis has not worked so well, as the below atmospheric humidity chart from www.climate4you.com reveals. (click on image to enlarge)
Now a new study discovers why the water vapor levels have not increased as predicted. Lammertsma et al. determine that as CO2 levels rise, vegetation responds in two ways: one, by absorbing more CO2 for food production, and two, releasing less water vapor. The scientists calculate that with this vegetation response, a doubling of atmospheric CO2 to 800ppm levels will cut in half the amount of atmospheric water vapor - that's called a major, natural, NEGATIVE feedback.
This negative feedback that will have a huge impact on the atmosphere's water vapor content is not included in any climate models that the IPCC, NASA and NOAA utilize. This may be a major reason why these models have continually failed in their predictions. Thus, current models' estimates of climate sensitivity evaporate, or if you prefer, transpire...or, is climate sensitivity kind of a climate model 'vaporware' chartacteristic.
"As carbon dioxide levels have risen during the last 150 years, the density of pores that allow plants to breathe has dwindled by 34 percent, restricting the amount of water vapor the plants release to the atmosphere, report scientists.....“The increase in carbon dioxide by about 100 parts per million has had a profound effect on the number of stomata and, to a lesser extent, the size of the stomata,” ...“Our analysis of that structural change shows there’s been a huge reduction in the release of water to the atmosphere.”...If there are fewer stomata, or the stomata are closed more of the day, gas exchange will be limited.....suggests that a doubling of today’s carbon dioxide levels — from 390 parts per million to 800 ppm — will halve the amount of water lost to the air, concluding in the second paper that “plant adaptation to rising CO2 is currently altering the hydrological cycle and climate..." [Emmy Lammertsma, Hugo de Boer, David Dilcher, Stefan Dekker, Andre Lotter, Friederike Wagner-Cremer, and Martin Wassen 2011:PNAS1 and PNAS2]
Read here. IPCC and national climate agency climate models have failed spectacularly at predicting the ENSO climate pattern changes that results in major regional weather conditions. A new peer-reviewed study helps expalin why the climate models fail consistently: the under estimation of both the Sun's impact and a powerful negative feedback ('ocean thermostat').
"A report in the December 3, 2010, issue of Science has reinforced what many scientists have suspected all along: variation in the Sun's output causes significant change in Earth's climate.....This new work indicates that even small variations in the Sun's output can have significant affect here on Earth. This is unsurprising, since the energy that drives Earth's climate comes from the Sun. Monsoon floods and decades long droughts are both part of the natural variation driven by our neighborhood star, but every climate fluctuation that causes human discomfort is blamed on anthropogenic global warming.....Their [Marchitto et al.] work is in agreement with the theoretical “ocean dynamical thermostat” response of ENSO to radiative forcing. Here is their description of the work: The influence of solar variability on Earth’s climate over centennial to millennial time scales is the subject of considerable debate. The change in total solar irradiance over recent 11-year sunspot cycles amounts to <0.1%, but greater changes at ultraviolet wavelengths may have substantial impacts on stratospheric ozone concentrations, thereby altering both stratospheric and tropospheric circulation patterns.....This model prediction is supported by paleoclimatic proxy reconstructions over the past millennium. In contrast, fully coupled general circulation models (GCMs) [IPCC climate models] lack a robust thermostat response because of an opposing tendency for the atmospheric circulation itself to strengthen under reduced radiative forcing." [Thomas M. Marchitto, Raimund Muscheler, Joseph D. Ortiz, Jose D. Carriquiry, Alexander van Geen 2010; Science 3 December 2010: Vol. 330 no. 6009 pp. 1378-1381]
Read here. There was a period during early 21st century when Greenland's ice mass reduction was happening due to its southeastern outlet glaciers melting and retreating. Most IPCC related alarmists claimed this was evidence of the infamous climate "tipping point" and predicted imminent catastrophic sea level rises would result.
Around 2006 the glacier retreats came to a screeching halt, thus stabilizing the ice sheet mass wastage and putting a lid on the typical alarmist's refrain that the Greenland ice sheet was disappearing. What stopped the glaciers melting? It was a natural, climatic negative feedback that took place (not the alarmist predicted, positive feedback induced tipping point).
A 2010 peer-reviewed study [Murray, T. et al. 2010] found that warm waters from the Atlantic were causing the melting of the glaciers; the melt waters from the glaciers decreased the temperatures of the surrounding waters thus the glaciers were no longer in contact with warm waters and the melting stopped.
"Murray et al. (eleven researchers) present evidence that suggests that the original ice wastage speedup "was the result of warm ocean waters coming into contact with the glaciers," and that this speedup "was probably terminated in part by increased discharge from the glaciers themselves, which increased ice sheet runoff and iceberg calving" that in turn "introduced additional cold water strengthening the East Greenland Coastal Current," which slowed glacier melting until warmer water again began to dominate the Current's waters.....write that their findings are suggestive of "a negative feedback that currently mitigates against continued very fast loss of ice from the ice sheet in a warming climate," and they thus conclude that "we should expect similar speedup and slowdown events of these glaciers in the future, which will make it difficult to elucidate any underlying trend in mass loss resulting from changes in this sector of the ice sheet." [Murray, T., Scharrer, K., James, T.D., Dye, S.R., Hanna, E., Booth, A.D., Selmes, N., Luckman, A., Hughes, A.L.C., Cook, S. and Huybrechts, P. 2010]
Read here. Almost all scientists agree that an increase in atmospheric CO2 will only raise global temperatures from 1.0 to 1.5 degrees Celsius. The IPCC is well aware of this established science, so they had scientists add a hypothetical positive feedback to the climate models, which would then produce predictions of much higher temperatures.
Terrestrial nature abhors positive feedbacks; that's why the climate is dominated by negative feedbacks. IPCC scientists hate natural negative feedbacks because they automatically reduce future global warming, and that's why the IPCC climate models either minimize negative feedbacks or entirely ignore them. Unfortunately for the IPCC Climategate scientists, the science research continues about natural climate feedbacks, which has now led to a new major negative feedback being identified in a new region of the world by peer-reviewed research.
Simply put, Geibert et al. found as warming increases, more sea ice and icebergs are melting in the Southern Ocean. This freshwater melt decreases the salinity of water, while increasing the iron content in layers of the sea, allowing for a huge increase in phytoplankton blooms. The new phytoplankton blooms cause more CO2 absorption (i.e. sequester CO2) from the atmosphere, which is then transported to the ocean depths.
Depending on the specific climate model, this natural negative feedback of CO2 sequestration is completley ignored or accounted for in minimal terms.
"The authors write that "the Southern Ocean (SO) plays a key role in modulating atmospheric CO2 via physical and biological processes,"...the eleven researchers -- hailing from Germany, New Zealand, South Africa and the United Kingdom.....state that their findings "imply that future changes in sea-ice cover and dynamics could have a significant effect on carbon sequestration in the SO." And if those changes were to include enhanced melting of Antarctic sea ice and icebergs, such as climate alarmists continually claim will occur, the planet's deep-ocean carbon transferal system would shift into a higher gear and effectively sequester greater amounts of CO2-carbon from the atmosphere, reducing its rate of rise and thereby reducing the strength of the CO2 greenhouse effect." [W. Geibert, P.Assmy, D.C.E. Bakker, C. Hanfland, M. Hoppema, L. Pichevin, M. Schröder, J. N. Schwarz, I. Stimac, R. Usbeck, A. Webb 2010]
Read here. That great Nobel thinker, CO2-spewing, money-grubbing, sex-crazed poodle of a politician, Al Gore, claimed in U.S. Senate testimony that global warming caused peetlands to release more CO2 and methane into the atmosphere, which is a "positive" feedback causing additional warming. Is the Gore-science prediction correct?
As usual, the answer is a definitive 'Nope.' In a new peer-reviewed study by Chinese researchers, it was found that peetlands provided a negative feedback mechanism as temperatures warmed. Now, who are going to believe? A selfish, self-centered, prima donna, Democrat political hack or real, peer-reviewed scientists?
"The authors write that peatland ecosystems "play a key role in the global carbon cycle and are influenced by global climate change," within which context the world's climate alarmists say the ongoing warming of the planet will lead to great releases of previously-sequestered carbon to the atmosphere in the form of CO2 and methane, which will greatly exacerbate global warming.....In describing their findings, the four researchers report that "obvious increasing trends in RERCA [recent rate of carbon accumulation (RERCA)] were observed in all peat cores,".....they say that the temporal increase in RERCA in the upper regions of the cores -- which likely corresponded to the warmest segment of their two-century study period -- "changed to a much greater extent in recent decades than in the earlier period of peat formation.".....this most recent study out of China indicates that the world's climate alarmists have got things one hundred and eighty degrees out of phase with reality in terms of the influence of earth's peatlands on the planet's temperature. These land types provide a negative feedback to global warming, whereby when they warm, they extract more -- not less -- CO2 from the atmosphere, applying a brake on rising temperatures..."
Read here, here, and here. As C3 readers have discovered, the multiple prediction failures of IPCC climate models are a result of many factors. A recent peer-reviewed study now adds a new one to the ever growing list.
Scientists, using empirical evidence from actual real-world experiments, find that the IPCC climate models' assumption that there is a huge positive feedback from an increase in temperatures, causing more CO2 release from soils and vegetation, causing more temperature increase, ad infinitum, is gigantically wrong. So wrong that it's even becoming obvious to the mainstream press: "
‘Runaway climate change’
‘unrealistic’, say scientists
Several of the critical points from the study:
"1. The climate is quite temperamental: countless factors are involved and many feedback mechanisms enhance effects such as the anthropogenic greenhouse effect. This makes it difficult to make predictions, especially as many processes in the Earth system are still not completely understood. 2. Particularly alarmist scenarios for the feedback between global warming and ecosystem respiration thus prove to be unrealistic.” 3. “It is still not possible to predict whether this attenuates the positive feedback between carbon dioxide concentration and temperature,” says Markus Reichstein. “The study shows very clearly that we do not yet have a good understanding of the global material cycles and their importance for long-term developments.” 4. “We were surprised to find that the primary production in the tropics is not so strongly dependent on the amount of rain,” says Markus Reichstein. “Here, too, we therefore need to critically scrutinize the forecasts of some climate models which predict the Amazon will die as the world gets drier.”"
Read here. Climate models have been programmed to produce a thawing of the tundra permafrost from human CO2-induced warming. This tundra "melting" will produce an explosion of CO2 and methane gas into the atmosphere. This is the mighty lore of the AGW hypothesis, thus models must be instructed to simulate this outcome. Fortunately, the AGW hypothesis and climate model programmers were wrong - like big time.
Turns out that Arctic warming encourages growth of vegetation, especially dense, ground covering shrubs, which cause the ground to be shaded (go figure). As a result, the permafrost does not thaw as expected and large amounts of greenhouse gases are not released. Voilà, a natural negative feedback!
""Permafrost temperature records, however, do not show a general warming trend during the last decade, despite large increases in surface air temperature. Data from several Siberian Arctic permafrost stations do not show a discernible trend between 1991 and 2000. Our results suggest that an expansion of deciduous shrubs in the Arctic triggered by climate warming may buffer permafrost from warming resulting from higher air temperatures.”....Blok et al. conclude “These results suggest that the expected expansion of deciduous shrubs in the Arctic region, triggered by climate warming, may reduce summer permafrost thaw. Increased shrub growth may thus partially offset further permafrost degradation by future temperature increases. Permafrost models need to include a dynamic vegetation component to accurately predict future permafrost thaw.”"
Read here and here. As with every unsubstantiated, speculative prediction made by alarmists and climate models, there is a grain of truth regarding melting tundra/permafrost releasing stored carbon dioxide. But researchers have discovered that when these melted areas are thawed, the explosion of new growth of vegetation becomes a positive CO2 sink that sequesters carbon dioxide in greater quantities than that released from the thaw. So instead of permafrost melting being a positive warming feedback, it actually becomes a negative feedback - funny how the climate always seems to do that in the end.
"In light of these compelling observations, it would appear that even if global warming were to accelerate and reach a tipping point that led to the demise of much of the world's permafrost, the subsequent "terrestrialization" of these regions would actually lead to more carbon being stored in the soils and vegetation of these parts of the world, rather than -- as climate alarmist claim -- more being lost."
And what about the release of methane (CH4) from melting?
"Delisle throws in another fast ball regarding methane (CH4) at the end of the article by stating “A second, rarely touched upon question is associated with the apparently limited amount of organic carbon that had been released from permafrost terrain in previous periods of climatic warming such as e.g. the Medieval Warm Period or during the Holocene Climatic Optimum. There appear to be no significant CH4-excursions in ice core records of Antarctica or Greenland during these time periods which otherwise might serve as evidence for a massive release of methane into the atmosphere from degrading permafrost terrains.”"
Just another reason why climate models are not an accurate representation of how the real-world climate actually works.
Below are depicted 3 temperature trends extending out to 2100. Using NCDC global temperature data, the three trends have a 2100 temperature spread of approximately 2.0°C. The green trend line represents the long-term trend, and it's end point almost perfectly matches the IPCC prediction of what temperatures will be, based on a doubling of CO2 levels from 280 ppm, the pre-industrial level (note: doubling of CO2 causes a 1.1°C increase and any further CO2 increase has almost zero impact on temperatures).
(click on image to enlarge)
The blue trend represents the cooling trend that developed in 2001. The red trend represents the "hot" trend that climate alarmists are concerned about since its appearance in the mid-1970's. Note that the red trend is above the IPCC prediction for the CO2 doubling mark, but it is well below the highest temperatures reached in the Medieval Warming Period.
What about those purple stars? Those are several of the climate model predictions that the IPCC and others state are likely. How could any of the historical trend lines possibly make gigantic shifts up to those purple stars? Well, it's called "positive" feedback. When temperatures reach the black/green star temperature, that's when the climate models' positive feedback supposedly does its magic and boosts temperatures to the purple stars. Unfortunately, when temperatures reached the Medieval gold/red star in the past, that old magical "positive" feedback moment did not occur, nor did it occur at other past times when temperatures were even higher.
Why not? Here's why not. And for good reason, positive feedback is unsustainable in nature unless we are talking about nuclear reactions, but that's not what the natural climate is about. Global temperatures may increase, but they won't do so in either an accelerated or runaway mode as global warming alarmists and climate modellers speculate.
Read here and here. [Upadate 4/6/2011: The below chart is a global representation of satellite data, not a measurement of a specific location, such as the stratosphere over Colorado, for example. For more 'C3' postings regarding greenhouse gases, go here.]
Another failure for the IPCC climate models and the overall CO2 AGW hypothesis that relies on a phantom positive feedback water vapor mechanism - the climate opera is at the curtain call and the phantom is AWOL. (click on image to enlarge)
"Increasing atmospheric CO2 does not by itself result in significant warming. The climate models assume a significant positive feedback of increased water vapor in order to amplify the CO2 effect and achieve the future warming reported by the IPCC....According to the IPCC, “Water vapour is also the most important gaseous source of infrared opacity in the atmosphere, accounting for about 60% of the natural greenhouse effect for clear skies, and provides the largest positive feedback in model projections of climate change.“"
Read here. The AGW hypothesis claims that the world's oceans have significantly warmed due to human CO2 emissions, and will continue to warm at an accelerated pace. The IPCC climate models were programmed to assume this ocean warming assumption. Reviewing the major research studies on this issue over the last decade, it's been found that the oceans have not significantly warmed, and more importantly, have actually cooled (lost heat) in recent years. This behavior runs counter to every IPCC climate model. In addition, one of the studies points to the oceans acting as a giant climate thermostat incorporating negative feedback mechanisms. The negative feedbacks prevent the global warming from achieving any type of "tipping point."
Read here. Naturally, many self-important (delusional?) individuals will be attending the Copenhagen (COP-15) conference in order to save the world from climate change. Most of the attendees, including celebrities, political leaders, and the MSM press, believe fervently in the climate "tipping points" (positive feedback) meme. The good news for any attendee's sanity, and for all of the rest of us humans, the actual climate science is reporting that negative feedbacks actually rule the realm. Conclusion? Tipping points are the urban legend of "elites" and ain't about to happen - they're hype.
Read here. Global warming alarmists claim thawing tundra will promote a positive global warming feedback; actual scientific research shows the opposite will be the case as more greenhouse gases are absorbed by the new plant life of the tundra.
Read here. It's not a secret to IPCC bureaucrats and climate modelers that biological aerosols represent a climate impact factor that are not accounted for, at all. Climate model prediction failures will continue until all climate influencers are incorporated into these "sophisticated" models.
Synopsis: CO2 increases cause marine algae to automatically help in formation of solar blocking clouds - negative feedback.
Source here. "Iodocompounds—created by marine algae—function as cloud condensation nuclei, which help create new clouds that reflect more incoming solar radiation back to space and thereby cool the planet."
Read here. Nope. Increasing water vapor is absolutely critical to the global warming theory as it is the positive feedback loop that CO2 emissions hypothetically cause. Thus, climate models predict higher humidity. Actual data shows the atmosphere being less humid - NO POSITIVE FEEDBACK! Surprised? (If so, go here and re-read all our previous postings about climate models' miserable record of predictions. You'll never be surprised by climate model failure again.)