A global temperature conundrum: Cooling or warming climate?
From the University of Wisconsin-Madison
MADISON, Wis. — When the Intergovernmental Panel on Climate Change recently requested a figure for its annual report, to show global temperature trends over the last 10,000 years, the University of Wisconsin-Madison’s Zhengyu Liu knew that was going to be a problem.
“We have been building models and there are now robust contradictions,” says Liu, a professor in the UW-Madison Center for Climatic Research. “Data from observation says global cooling. The physical model says it has to be warming.”
Writing in the journal Proceedings of the National Academy of Sciences today, Liu and colleagues from Rutgers University, the National Center for Atmospheric Research, the Alfred Wegener Institute for Polar and Marine Research, the University of Hawaii, the University of Reading, the Chinese Academy of Sciences, and the University of Albany describe a consistent global warming trend over the course of the Holocene, our current geological epoch, counter to a study published last year that described a period of global cooling before human influence.
The scientists call this problem the Holocene temperature conundrum. It has important implications for understanding climate change and evaluating climate models, as well as for the benchmarks used to create climate models for the future. It does not, the authors emphasize, change the evidence of human impact on global climate beginning in the 20th century.
“The question is, ‘Who is right?'” says Liu. “Or, maybe none of us is completely right. It could be partly a data problem, since some of the data in last year’s study contradicts itself. It could partly be a model problem because of some missing physical mechanisms.”
Over the last 10,000 years, Liu says, we know atmospheric carbon dioxide rose by 20 parts per million before the 20th century, and the massive ice sheet of the Last Glacial Maximum has been retreating. These physical changes suggest that, globally, the annual mean global temperature should have continued to warm, even as regions of the world experienced cooling, such as during the Little Ice Age in Europe between the 16th and 19th centuries.
The three models Liu and colleagues generated took two years to complete. They ran simulations of climate influences that spanned from the intensity of sunlight on Earth to global greenhouse gases, ice sheet cover and meltwater changes. Each shows global warming over the last 10,000 years.
Yet, the bio- and geo-thermometers used last year in a study in the journal Science suggest a period of global cooling beginning about 7,000 years ago and continuing until humans began to leave a mark, the so-called “hockey stick” on the current climate model graph, which reflects a profound global warming trend.
In that study, the authors looked at data collected by other scientists from ice core samples, phytoplankton sediments and more at 73 sites around the world. The data they gathered sometimes conflicted, particularly in the Northern Hemisphere.
Because interpretation of these proxies is complicated, Liu and colleagues believe they may not adequately address the bigger picture. For instance, biological samples taken from a core deposited in the summer may be different from samples at the exact same site had they been taken from a winter sediment. It’s a limitation the authors of last year’s study recognize.
“In the Northern Atlantic, there is cooling and warming data the (climate change) community hasn’t been able to figure out,” says Liu.
With their current knowledge, Liu and colleagues don’t believe any physical forces over the last 10,000 years could have been strong enough to overwhelm the warming indicated by the increase in global greenhouse gases and the melting ice sheet, nor do the physical models in the study show that it’s possible.
“The fundamental laws of physics say that as the temperature goes up, it has to get warmer,” Liu says.
Caveats in the latest study include a lack of influence from volcanic activity in the models, which could lead to cooling — though the authors point out there is no evidence to suggest significant volcanic activity during the Holocene — and no dust or vegetation contributions, which could also cause cooling.
Liu says climate scientists plan to meet this fall to discuss the conundrum.
“Both communities have to look back critically and see what is missing,” he says. “I think it is a puzzle.”
The study was supported by grants from the (U.S.) National Science Foundation, the Chinese National Science Foundation, the U.S. Department of Energy, and the Chinese Ministry of Science and Technology.
What they are really saying:
“We know with certainty that 1 +1 = 3, but observations tells us that it is 2 … We need more funds to investigate this!“
Hey I’m just a guy who wears jeans and tennis shoes most of the time but I have a wild notion for Lui to ponder.
The fundamental laws of physics say that as the temperature goes down, it has to get colder.
This is standard AGW trash publication feeding the warmist trolls. I don’t know why this site gives continues to quote them/give them so much attention They should simply be avoided as it tends to give them credence. We are past the time that anything they produce is credible. Refer to Steven Goddard.(and numerous others) for evidence of outright lies and fraud.by the AGW establishment (icluding Nature Publication ect)
These wretched people still can’t allow themselves to admit the obvious; the models are completely useless.
I’m not sure they will even when the dumbest citizen with the IQ of doorknob has positively concluded the complete lack of any utility.
The only upside of this is… the ever expanding body of evidence of their ineffectiveness and the increasingly desperate excuses are going to deliver a bonanza in terms of entertainment value for WUWT readers.
When the wind speed goes up it is supposed to get windier. Innit?
Lewis P Buckingham says:
August 11, 2014 at 8:32 pm
I believe the temperature went out.
To: mod, I like the like button but for some reason world press wants info from me I am not inclined to give is there another way around ( Apologize for using the thread), Asybot
richard verney says:
August 11, 2014 at 8:25 pm
Thanks Richard.
An outstanding 2nd round post and a nice to read a clear, well articulated follow-on to rgbatduke’s round one on this thread. It is so past time that Climate Science started cleaning up the mess that political viewpoint activism has wrought on science.
With every passing day, I am happier and happier about Anthony’s “I Support Climate ^Science Change” on my truck. Buy one. Support Anthony’s blog. Climate science is entering a crisis period our grandchildren will read about, much like Galileo’s confrontations 400 years ago with the Vatican.
JMO
Looks like a brewing moment before the conflagration where both sides armies face off then proceed to kill each other to the last man en echelon style.
Good !
I’ll watch from Shenandoah Mountain. Later pick the pockets of the dead. Lots of trinkets to sell in San Francisco. Good money.
🙂
What if climate models said the sun would not rise and it did anyway?
Would it be a toss up over what was wrong?
Tony B says:
August 11, 2014 at 7:22 pm
paraphrase, “CAGW proponents …. strategies on how to jump from the consensus train before it plummets into the canyon.”
An appropriate Youtube video on what the CAGW train looks like right now.
Allen63 says:
August 11, 2014 at 3:43 pm
==============================================
What was the temperature in the oceans prior to the melt? Would the Ice Age level oceans have been warmer on average than today,s oceans due to the lower sea level?
Another thought, would the rush of cold water raise warmer waters to where they would become part of the warming force that breaks the glaciation and helps lead to the interglacial?
The empirical data is right, always the empirical data.
And the mere fact that he is asking that question shows how bad climate science is.
Go back to high school, Mr. Liu, to learn, not to teach.
“… as regions of the world experienced cooling, such as during the Little Ice Age in Europe… ”
Please somebody verify, the LIA surely was NOT a “regional” event but a global event wasn’t it?
Andrew N says:
August 11, 2014 at 4:24 pm
The Bible says it circles the Earth”
=======================================================
Strange, I don’t remember that section of the Bible where that is stated. Perhaps you meant to say that men who believed in the Bible also thought the Sun circled the Earth. There is a difference.
“Yet, the bio- and geo-thermometers used last year in a study in the journal Science suggest a period of global cooling beginning about 7,000 years ago and continuing until humans began to leave a mark, the so-called “hockey stick”
Prof. Liu, the fundamental laws of physics do not include the hockey stick and climate models. It has to be cooling because that was the interglacial optimum (or maximum). Common knowledge to geologists but surprising news to climate modelers and hockey stickers.
My eyeballs say it will take only 18-24 more months of the plateau for the lower line of the 95% envelope to be breeched.
Madison, Wisconsin – 25 square miles surrounded by reality.
Could this, perhaps, become known as the Liu paper?
Now it is definitely time to replace reality.
Isn’t “Physical Model” a strange phrase ? Why are they using the word “physical” ?
goldminor August 11, 2014 at 11:01 pm
and Louis August 11, 2014 at 6:49 pm
My sarcastic comment was in relation to the interpretation of the Bible in relation to Galileo in front of the Roman Inquisition regarding his support of heliocentrism.
In 1616, an Inquisitorial commission unanimously declared heliocentrism to be “foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture.”
As a counter to the many comments here that are either ad hominem or off-topic, I offer the following references that falsify many of the points raised in Zhengyu Liu’s paper. These references show that many of the points are not relevant to the comparisons between theory and observations.
Earth’s Energy Budget
The radiation budget is the most important tool in quantifying the warming or cooling of the Earth. Moreover, the data for radiation budget has been acquired by several satellites for a long enough period to allow testing the theoretical models. Even better, the NASA researchers who investigate the data quality and their adequacy operate under different managers, apparently with different terms of reference.
The current global energy budget can be derived either from satellite data or from theory using a few parameters, by the “classical method”. The theoretical approach is described by Goody and Yung, Atmospheric Radiation: Theoretical Basis, 2nd Ed. 1995 (1989 hardback).
Goody and Yung is the standard text used by writers of atmospheric physics textbooks. In the Introduction, the authors say, “Historically, before large computers became available, two classes of study developed, one synthetic but limited in scope and the other descriptive but aiming at completeness…..These classical methods, rather than the theory and results from large numerical models, are emphasized in this book.” The URL is:.
http://books.google.com/books?id=Ji0vfj4MMH0C&printsec=frontcover&dq=goody+and+yung+Atmospheric+Radiation&hl=en&sa=X&ei=ScnlU_KSMYq48gWT54D4Bg&redir_esc=y#v=onepage&q=goody%20and%20yung%20Atmospheric%20Radiation&f=false
The way to tell whether or not Goody and Yung is the basis for a textbook’s approach is to look for a dozen or more pages of mathematical equations. Murray Salby’s Physics of the Atmosphere and Climate (Cambridge U Press, 2012) is a good example of a clear presentation of the leading classical method. See Chapter 8, Radiative transfer, p.203. Those who do not have the book can get an general idea from this URL:
http://books.google.com.my/books?id=CeMdwj7J48QC&q=radiation#v=snippet&q=radiation&f=false
Both Goody & Yung and Salby calculate the Earth’s energy budget from formulas by plugging in various parameter values. Goody and Yung use 1400 Watts/m2 as the solar constant and 0.31 for albedo. Salby uses 1372 W/m2 and 0.30 for albedo. Both use 4 as the ratio of the Earth’s surface area (4Pi * R2) to the area of the disc (Pi * R2) as seen from space.
Goody and Yung derived a value for LW radiation from TOA of 108.5 W/m2 and Salby derived 102.9 W/m2. The published ERB figure based on satellite observations was 107 W/m2 (Trenberth, j. Climate, 1997).
In 2009, a team comprising five NASA and NIA scientists plus two private sector scientists published corrected values for all three parameters and demonstrated that the errors in calibration of the satellites were substantial in comparison to the energy imbalance upon which rests alarmist claims of global warming.
In 2005, James Hansen and others took a different approach from both Goody and Yung and from those who used satellites to computer the Earth’s energy budget. (Earth’s Energy Imbalance: Confirmation and Implications (Science 3 June, Vol. 1434 308)) Hansen et al found an imbalance of +0.85 W/m2 as the excess of incoming energy over that re-emitted by the Earth. This excess was imputed to storage of the excess heat by the oceans.
In 2009, a different group led by NASA’s Norman Loeb reported their study, “Toward Optimal Closure of the Earth’s Top-of-Atmosphere Radiation Budget” based on satellite observations. (J.of Climate, AMS, V.22, p.748.) This group found that the parameters used for the classical method cannot account for satellite observations. Work by the NIS gives 1361 W/m2 as the solar constant S. Previous bias Bias +1.00 W/m2.
Correction for the Earth’s oblateness gives 4.0034 as the denominator N in the formula S/N instead of 4 as used in the classical approach. Previous bias +0.29 direct and indirect +0.16 W/m2 via latitude weighting, total potentially 0.45 W/m2.
Correction to albedo to 0.293 instead of the usual 0.30. Bias +0.30 W/m2.
The authors state, “We assume the ‘‘true’’ global net flux imbalance during the CERES period considered is +0.85+/-0.15 W m2, based on Hansen et al. (2005). ”
The authors summarize the combined effect of all of these errors. When estimates of solar irradiance, SW and LW TOA fluxes are combined, taking account of +0.85+/-0.15 W/m2 heat storage by the oceans, the possible range of TOA flux becomes ) minus 2.1 to plus 6.7 W/m2,
In passing, I note that Loeb and his team do not refute Hansen’s estimate of +0.85 W/m2 but merely show that the satellites show that previous satellite estimates of TOA flux had errors due to instrument miscalibration. The former total TOA flux of 341.0 was corrected to 339.1, an adjustment of minus 1.9. The error was approximately double the imbalance reported by Hansen et al.
In 2011, Hansen and others revised the earlier estimates of energy imbalance to be +0.58 W/m3.
(Earth’s energy imbalance and implications, Atmos. Chem. Phys., 11, 13421–13449, 2011)
“The inferred planetary energy imbalance, 0.58±0.15 Wm−2 during the 6-yr period 2005–2010, confirms the dominant role of the human-made greenhouse effect in driving global climate change.” (Abstract) and later in the text “The importance of the uncertainty in aerosol forcing is
highlighted by considering two specific values of the net (GHG + aerosol) forcing: +1 Wm−2 and +2 Wm−2. Either of these values has a good chance of being correct….”
In passing, I note that the error bars for the figure 0.58 W/m2 do not appear to take account of the uncertainty in aerosol forcing. The authors therefore signify that the figure 0.58 W/m2 is what professors used to tell students constitutes “empty precision”. This criticism is supported by generally recognition that sea temperature data is still too uncertain to be the basis for estimating an imbalance as precise as +0.58+/-0.15 W/m2.
Loeb’s team of authors based their estimates on satellite data while Hansen’s studies were based on ocean temperature data. Hansen’s study indicates where the excess heat was stored. Loeb’s study calls into question whether or not there was any excess heat to be stored.
In August , 2000, Hansen et al published in PNAS the paper, Global warming in the twenty-first century: An alternative scenario (vol. 97 no. 18).
“A common view is that the current global warming rate will continue or accelerate. But we argue that rapid warming in recent decades has been driven mainly by non-CO2 greenhouse gases
(GHGs), such as chlorofluorocarbons, CH4, and N2O, not by the products of fossil fuel burning, CO2 and aerosols, the positive and negative climate forcings of which are partially offsetting.”
In my opinion, Hansen and his team were admitting that alarmist statements regarding TOA energy imbalance. I interpret this paper as a concession to other NASA researchers that the TOA energy imbalance is too small to be estimated with certainty.
In 2012, Loeb and his team published the paper, Observed changes in top-of-the-atmosphere
radiation and upper-ocean heating consistent within uncertainty. (NATURE GEOSCIENCE j VOL 5 j FEBRUARY 2012)
“Coupled Model Intercomparison Project 3 (CMIP3) simulations for the A1B scenario from 15 coupled atmosphere-ocean models exhibit a large spread in annual mean net TOA flux during the past decade, ranging from 0.09 to 1.5Wm-2 (Fig. 3b, grey bar). Interannual variability of net TOA flux in the models is surprisingly large: the standard deviation in model net TOA flux between 2001 and 2010 exceeds that from the observations in 11 of the 15 models considered.”
I ignore the term “observations” in the last sentence because it is not certain whether these are observations of nature or observations of model behavior.
The main points of the paper are that (1) the variations in sea temperatures are not statistically significant and (2) the modal value for TOA flux for the 15 models was 0.75 W/m2 with a high (unstated) standard deviation.
In my opinion, this paper effectively demolishes the work of Hansen et al (2005, 2011) by showing that the satellite energy estimates are more certain than the estimates based on ocean temperature data.
When read together with the 2009 paper (J. Climate) by the same team, this paper shows that the satellite estimates are not certain enough to demonstrate that the net TOA flux trends monotonically upwards. There appear to be substantial variations sufficient to flip from positive to negative net flux inter-annually. The magnitude of the TOA flux when positive appears to be small enough to be overwhelmed by internal variability as observed in the ENSO (considered in the 2012 Nature paper) and other by ocean oscillations such as the AMO and PDO.
Finally, this review of five papers by (mostly) NASA scientists between 2000 and 2012 reveals that global warming may be an artifact of the acquisition and processing of the data filtered through confirmation bias initially established by the imprecision inherent in the Goody & Yung approach to the “classical method” of estimating the Earth’s energy budget that is taught in all atmospheric physics courses.
The classical physics approach is not wrong. It is merely too blunt a tool for determining TOA flux. The billions spent on climate satellites is starting to pay off. And fortunately, many scientists in NASA and other government research establishments are not blinkered by global warming activism.
Sorry, I omitted a closing bracket at “Historically, before large computers became available,/b>”
[Fixed. ~mod.]