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Man-Made Global Warming: Settled Science?

We've taken the watch apart, but we still don't know how it works.

INTRODUCTION:

I started writing this almost as soon as I accepted Brian Crawford's challenge in another post: list five peer-reviewed studies, published in scientific journals, which deny that Mankind is ultimately responsible for global warming ("anthropogenic global warming," or "AGW"), and enjoy lunch at his treat.

Editor's note: The challenge from Brian Crawford came in a comment he posted on the blog "Fall Officially Begins This Saturday." 

I love my food: how could I possibly resist?

But within 2 hours, I had 2,000+ such papers to choose from, and in 24 hours my "editorial" had become a 20+ page "review of the literature." Since I’m only looking for lunch (not groceries for life), I limited my list to 5 points which question key aspects of the AGW paradigm, with 4 journal-published, peer-reviewed studies for each point: 1 for each dollar of Mr. Crawford’s potential tab.

As a result, this list is tiny. Anyone interested can use this as a starting point, and go from there. Also, none of the many papers which support AGW theories are found here, but I think that side of the story is already well-publicized.

No doubt, some will either denigrate or applaud this effort. Some will use politics, some will use science; some will quote “the experts,” and some will just need to say something. Do not expect my response to any of it, but all of it is fine with me.

You see, I treasure the freedom of speech, because it means the freedom of competing ideas. Good ideas are honed and refined by questioning, thrive on open discussion. Bad ideas require the silencing of the debate, or they get revealed for what they are: bad. So when someone, however “expert,” however high-ranking or respected, tells me “the debate is over, sit down and shut-up….” Well, I want to know "why?" And they'd better have a good reason.

The UN's Intergovernmental Panel on Climate Change (IPCC) might be generally right about the AGW issue. The Non-governmental International Panel on Climate Change’s (NIPCC) conclusions might be little beyond hot air. But the science, as such, is nowhere close to being "decided," no matter what Al Gore or Rush Limbaugh have to say, and I don't appreciate the self-appointed disciples of either side trying to shut off the debate when it's only just begun.

A BIT OF THE SCIENCE:

1) HASN'T THE 20th CENTURY BEEN UNUSUALLY HOT, OR SEEN AN UNUSUAL RATE OF WARMING? - The Current Warming Period is neither unusual, nor remarkable, nor unprecedented in recent human history. 

a) Weichao Wu, Wenbing Tan, Liping Zhou, Huan Yang, Yunping Xu: Sea surface temperature variability in southern Okinawa Trough during last 2700 years. Geophysical Research Letters, (2012) currently in press. DOI:10.1029/2012GL052749  (*My illustration is from this source.)

b) Joan Bunbury, Konrad Gajewski: Temperatures of the past 2000 years inferred from lake sediments, southwest Yukon Territory, Canada. Quaternary Research, (03 May 2012) Volume 77, Issue 3, pp.355-367.  http://dx.doi.org/10.1016/j.ygres.2012.01.002

c) Michael-Shawn Fletcher, Patricio Iván Moreno: Vegetation, climate and fire regime changes in the Andean region of southern Chile (38°S) covaried with centennial-scale climate anomalies in the tropical Pacific over the last 1500 years Quaternary Science Reviews, (16 July 2012) Volume 4, Pages 46–56.  http://dx.doi.org/10.1016/j.quascirev.2012.04.016

d) Scott Mensing, John Korfmacher, Thomas Minckley, Robert Musselman: A 15,000 year record of vegetation and climate change from a treeline lake in the Rocky Mountains, Wyoming, USA, The Holocene, (July 2012) vol. 22 no. 7 p.739-748. Available online prior to publishing December 2011. DOI:10.1177/0959683611430339

2) AREN’T WE PUTTING MORE CO2 IN THE ATMOSPHERE THAN EVER? – Mankind’s emissions of CO2 are at an all-time high. In spite of this, current atmospheric CO2 levels (<400ppm) are closer to record lows (~200ppm) than record highs (>4,000ppm), and the current rate of CO2 rise is not unusual in the natural record.

a) Daniel H. Rothman: Atmospheric carbon dioxide levels for the last 500 million years, PNAS [Proceedings of the National Academy of Sciences of the USA], (02 April 2002) vol. 99 no. 7 pp.4167-4171.  Published online before print 19 March 2002.  DOI:10.1073/pnas.022055499

b) Friederike Wagner, Sjoerd J. P. Bohncke, David L. Dilcher, Wolfram M. Kürschner, Bas van Geel, Henk Visscher: Century-scale shifts in early Holocene atmospheric CO2 concentration, Science, (18 June 1999) Vol. 284 no. 5422 pp.1971-1973. DOI:10.1126/science.284.5422.1971

c) Gregory J. Retallack: A 300-million-year record of atmospheric carbon dioxide from fossil plant cuticles, Nature, (17 May 2001) vol.411, pp.287-290. DOI:10.1038/35077041

d) Michael D. Dettinger, Michael Ghil: Seasonal and interannual variations of atmospheric CO2 and climate, Tellus Series B: Chemical and Physical Meteorology [International Meteorological Institute, Stockholm], (February 1998) Volume 50, Issue 1, pages 1–24. DOI:10.1034/j.1600-0889.1998.00001.x

3) DON'T GREENHOUSE GASSES LIKE CO2 DRIVE TEMPERATURE CHANGE? – Despite CO2's known greenhouse properties, changes in atmospheric CO2 lag behind changes in temperature on all observed time-scales.

a) Ole Humlum, Kjell Stordahl, Jan-Erik Solheim: The phase relation between atmospheric carbon dioxide and global temperature, Global and Planetary Change, (2012). Available online 30 August 2012.  http://dx.doi.org/10.1016/j.gloplacha.2012.08.008

b) Lowell Stott, Axel Timmermann, Robert Thunell: Southern hemisphere and deep-sea warming led deglacial atmospheric CO2 rise and tropical warming, Science, (19 October 2007) Vol. 318 no. 5849 pp. 435-438. DOI:10.1126/science.1143791

c) Manfred Mudelsee: The phase relations among atmospheric CO2 content, temperature and global ice volume over the past 420 ka, Quaternary Science Reviews, (February 2001) Volume 20, Issue 4, Pages 583–589. http://dx.doi.org/10.1016/S0277-3791(00)00167-0

d) Bärbel Hönisch, N. Gary Hemming, David Archer, Mark Siddall, Jerry F. McManus: Atmospheric carbon dioxide concentration across the mid-Pleistocene transition, Science, (19 June 2009) Vol. 324, no. 5934, pp.1551-1554 . DOI:10.1126/science.1171477

4) BUT IF CO2 ISN'T DRIVING CLIMATE CHANGE, WHAT IS? - Climate change throughout human history closely follows solar activity cycles.

a) C. de Jager, S. Duhau: Episodes of relative global warming, Journal of Atmospheric and Solar-Terrestrial Physics, (2009) vol. 71, no. 2, pp.194-198. DOI:10.1016/j.jastp.2008.11.013

b) Graeme T. Swindles, R. Timothy Patterson, Helen M. Roe, Jennifer M. Galloway: Evaluating periodicities in peat-based climate proxy records, Quaternary Science Reviews, (18 May 2012) Volume 41, pp.94–103. http://dx.doi.org/10.1016/j.quascirev.2012.03.003

c) Jinglu Wu, Zicheng Yu, Hai'Ao Zeng, Ninglian Wang: Possible solar forcing of 400-year wet-dry climate cycles in northwestern China, Climatic Change, (2009) vol.96:473-482. DOI:10.1007/s10584-009-9604-4

d) Ilya G. Usokin, Sami K. Solanki, Manfred Schüssler: Millennium-scale sunspot number reconstruction: evidence for an unusually active Sun since the 1940s, Physical Review Letters [American Physical Society], (19 November 2003) Vol. 91, Issue 21 DOI:10.1103/PhysRevLett.91.211101

5) BUT HOW CAN A NEAR-CONSTANT SUN DRIVE LARGE CHANGES IN CLIMATE? – Mechanisms exist which can turn minor solar variations into large climate impacts on both regional and global scales.

a) Mukul Sharma: Variations in solar magnetic activity during the last 200,000 years: is there a Sun–climate connection?, Earth and Planetary Science Letters, (10 June 2002) Volume 199, Issues 3–4, pp.459–472. http://dx.doi.org/10.1016/S0012-821X(02)00516-2

b) Murry Salby, Patrick Callaghan: Connection between the solar cycle and the QBO: the missing link, Journal of Climate [American Meteorological Society], (January 2000) Volume 13, Issue 2, pp.328–338.  http://journals.ametsoc.org/doi/full/10.1175/1520-0442%282000%29013%3C0328%3ACBTSCA%3E2.0.CO%3B2

c) Gerald A. Meehl, Julie M. Arblaster, Katja Matthes, Fabrizio Sassi, Harry van Loon: Amplifying the Pacific climate system response to a small 11-year solar cycle forcing, Science (28 August 2009) Vol. 325, no. 5944, pp.1114-1118. DOI:10.1126/science.1172872

d) B. Kirov, K. Georgieva: Long-term variations and interrelations of ENSO, NAO and solar activity, Physics and Chemistry of the Earth, Parts A/B/C, (2002) Volume 27, Issues 6-8, pp.441-448. http://dx.doi.org/10.1016/S1474-7065(02)00024-4

Bonus) BUT ISN'T LESS CO2 BETTER FOR US ALL ANYWAY? - CO2 is a trace gas, non-toxic to human beings, which is essential to plant life in particular and to the biosphere as a whole. Increased atmospheric CO2 levels benefit the entire biosphere.

a) Anabel Robredo, Usue Pérez-López, Hector Sainz de la Maza, Begoña González-Moro, Maite Lacuesta, Amaia Mena-Petite, Alberto Muñoz-Rueda: Elevated CO2 alleviates the impact of drought on barley improving water status by lowering stomatal conductance and delaying its effects on photosynthesis, Environmental and Experimental Botany, (April 2007) Volume 59, Issue 3, pp.252–263. http://dx.doi.org/10.1016/j.envexpbot.2006.01.001

b) Heather R. McCarthy, Ram Oren, Hyun-Seok Kim, Kurt H. Johnson, Chris Maier, Seth G. Pritchard, Micheal A. Davis: Interaction of ice storms and management practices on current carbon sequestration in forests with potential mitigation under future CO2 atmosphere, Journal of Geophysical Research, (08 August 2006) Vol. 111, D15103. DOI:10.1029/2005JD006428

c) Shannon L. LaDeau, James S. Clark: Rising CO2 levels and the fecundity of forest trees, Science, (06 April 2001) Vol. 292, no. 5514, pp.95-98. DOI:10.1126/science.1057547

d) G. Geoff Wang, Sophan Chhin, William L. Bauerle: Effect of natural atmospheric CO2 fertilization suggested by open-grown white spruce in a dry environment, Global Change Biology, (March 2006) Volume 12, Issue 3, pp.601–610. Available online 17 January 2006. DOI:10.1111/j.1365-2486.

IN SUMMARY:

It has been proclaimed far and wide that the “mainstream” scientific consensus has “settled” in favor of AGW, but as you can see from this small sample, that is simply not the case. If this is not enough peer-reviewed science to persuade you of a genuine debate, try out this list of papers, among others: http://www.populartechnology.net/2009/10/peer-reviewed-papers-supporting.html. There’s enough there to keep you busy for a little while.

If you review the science and still come to the conclusion that Mankind is to blame for the warming of our climate, that's fine with me. You’ll need to be okay with not understanding why CO2 lags temperature, why its predicted effects do not match observed climate measurements, or why the IPCC's general circulation models cannot predict short-term, regional, or even past climate changes accurately.

By the same token, those who come to the conclusion that AGW is "wrong" have to explain why the urban heat island effect doesn't significantly influence regional or global climate; why observed climate changes are far larger than changes in total solar irradiance can account for; and why it is unreasonable to assume that human civilization has a measurable affect on regional/global climates, when atmospheric evidence of that civilization is observable from beyond Lunar orbit.

Both sides have plausible answers to those questions, and as I've said, a reasoned decision either way is fine with me, as long as it's based on your best understanding of the information. Basing your decision solely on political concerns is probably not a good idea, though you certainly can if you want.

But hopefully you can now see for yourself that when it comes to climate change, anyone who tells you that the science is "settled," "well understood" or "decided" probably has not seen the evidence, or just doesn’t want you to see it.

So, Brian: what do you like for lunch?

North Georgia Weather September 27, 2012 at 01:39 pm
Good article Dave! And good luck with Brian! :-))
NJ4America September 27, 2012 at 01:45 pm
I cause a little "Man Made" Global Warming after I eat chili.
Brian Crawford September 27, 2012 at 01:51 pm
Dave I applaud the effort but I'm not sure this satisfies my challenge, which was:
"For the record, "peer reviewed" means a study published in a scientific journal and reviewed by one's fellow scientists, not paid for by some Tea Party "think tank". Find five that deny the existence of man-made climate change and I'll buy you lunch." I believe the studies you cite meet the definition of "peer reviewed" I set forth but you offer no links or quotes that show that any of them "deny the existence of man-made climate change." I'll buy you that lunch for your good faith effort but I'm interested to know if our fellow Patch readers think you met the test. What say ye Patchies?
North Georgia Weather September 27, 2012 at 03:18 pm
LOL!!!! Methane releases are indeed warming the atmosphere... hard to stop that! :-))
Maybe the government needs to supply everyone with Bean-O! :-))
C.J. September 27, 2012 at 03:23 pm
Dave,
After sampling a few of these studies, I can see that they're peer reviewed and published by reputable academic journals. However, they don't say what you think they say. For example, the "Episodes of Global Warming" study simply confirms that solar activity can influence average temperatures. No climate scientist denies that. But this study doesn't state or imply that current extreme temperatures are exclusively affected by solar activities. In addition, the piece, "Vegetation, climate and fire regime changes in the Andean region of southern Chile..." studies moisture patterns in a particular region over 1,500 years and primarily looks at the impact of El Niño. You're essentially concluding that if CO2 emissions are either excluded from or controlled for in any study looking at temperatures or climate, then that study, must necessarily deny the existence of man-made climate change. That, my friend, is ludicrous. If I apply your logic, the first study that I mentioned above denies the influence of El Niño on climate and the second study denies the influence of solar activity on climate. I don't have time to look through every study, but if you have a study that specifically concludes that CO2 emissions are not influencing global temperatures, as Brian challenged you to find, then I'll be happy to look at it. But from the samples that I've seen, you're making inferences from these studies that are huge leaps of logic.
C.J. September 27, 2012 at 03:38 pm
Also Dave, if you haven't already read this editorial by the climate-change skeptic who was hired by the Koch brothers with the expectation that he would tell them what they wanted to hear, you should (as well as any underlying data that you can find).
He addresses all the issues that skeptics bring up: biases from urban heating, biases from data selection, biases from poor station quality, biases from human intervention and data adjustment, plus influences on temperature by volcanic eruptions, El Niño, the Gulf Stream, solar activity, and growing world population. They conclude that those influences are not "statistically significant." Rather, "by far the best match was to the record of atmospheric carbon dioxide, measured from atmospheric samples and air trapped in polar ice..." http://www.nytimes.com/2012/07/30/opinion/the-conversion-of-a-climate-change-skeptic.html?_r=4&pagewanted=all His studies conclude, "Berkeley Earth has just released analysis of land-surface temperature records going back 250 years, about 100 years further than previous studies. The analysis shows that global warming is real, and the best explanation of the temperature trend is a combination of volcanoes and CO2." http://berkeleyearth.org/
C.J. September 27, 2012 at 04:00 pm
Dave, Dave, Dave. At the risk of sounding like a nine-year old girl, I can't help but cry out, "OH MY GOD!"
I just looked at another one of the studies that you placed under the heading "The Current Warming Period is neither unusual, nor remarkable, nor unprecedented in recent human history." This study, "A 15,000 year record of vegetation and climate change from a treeline lake in the Rocky Mountains, Wyoming, USA" specifically looks at the potential impact of climate change on the lakes and trees in Rocky Mountains. In other words, it accepts that climate change is real, and tries to predict how it will affect a particular region of the country. The study predicts "lower lake levels during an extended dry period with warmer summer temperatures and treeline advance." I'm going to give you the benefit of the doubt and assume that somebody mislead you. They found a bunch of studies related to climate, completely manufactured what these studies found, and slapped them online assuming, I suppose, that nobody would actually read them. I'm actually embarrassed for you. http://hol.sagepub.com/content/22/7/739.full.pdf+html
Dave Ballard September 27, 2012 at 04:57 pm
Before feeling too embarrassed for me, C.J., you might want to re-read that abstract you quoted:
"Between 6000 and 5000 cal. yr BP sediments become increasingly organic and sedimentation rates increase. We interpret this as evidence for lower lake levels during an extended dry period with warmer summer temperatures and treeline advance." So, not a prediction, but an observation from 5-6 thousand years ago. Thanks for your comments.
C.J. September 27, 2012 at 06:18 pm
Again, you're drawing conclusions that don't exist. Yes, the study recognizes that the globe has warmed and cooled over time. Again, every climate scientist agrees. That is not the same thing as saying that this current warming period is neither unusual, nor remarkable, nor unprecedented. The very first line of the study states, "future climate projections predict warming at high elevations that will impact treeline species..."
Still embarrassed for you.
North Georgia Weather September 27, 2012 at 06:24 pm
Trying to extrapolate data from thousands of years ago, or even hundreds of years ago using indirect methods and using that as "fact" is not very scientific.
"...plus influences on temperature by volcanic eruptions, El Niño, the Gulf Stream, solar activity, and growing world population. They conclude that those influences are not "statistically significant." Not statistically significant??? Really??? Things that we know effect the temperature of the world are not statistically significant??? Please.
C.J. September 27, 2012 at 06:45 pm
NGW,
Take it up with these guys: Richard Muller, Founder and Scientific Director, Professor of Physics Robert Rohde, Lead Scientist,Physicist David Brillinger, Statistical Scientist Judith Curry, Climatologist Don Groom, Physicist Zeke Hausfather, Environmental Economist Robert Jacobsen, Professor of Physics Saul Perlmutter, Professor of Physics Arthur Rosenfeld, Professor of Physics, Former California Energy Commissioner Sebastian Wickenburg, Ph.D. Candidate in Physics Charlotte Wickham, Statistical Scientist Jonathan Wurtele, Professor of Physics http://berkeleyearth.org/about-us/
North Georgia Weather September 27, 2012 at 07:17 pm
I read it. I've also read many other articles that bring up the same point I do.
The problem here is that nothing is black and white with this issue. Intelligent people disagree on "exactly" what component of the warming is man made.
Michael Robinson September 28, 2012 at 04:02 pm
Nope. Citing a bunch of documents and saying "see for yourself" doesn't tell anyone anything. It doesn't help that most scientific literature is locked up in proprietary research databases.
Dave Ballard September 28, 2012 at 04:27 pm
Telling people "the argument is over" and not bothering to cite any legitimate science whatsoever is also not helpful, I find. This often happens in the popular media (c.f. other posters' citations of wikipedia and various editorials) so perhaps we could consider this post a step up?
All of the abstracts are available for free online, and many of these papers' full text PDFs are available for free as well, though you may have to spend some time Google-ing to find them. Finally, the link I gave toward the end of the post has links to many, many studies which include free links to the full PDF files. Thanks for reading, Michael. I appreciate your comments.
Brian Crawford September 28, 2012 at 04:32 pm
Dave, let me know when you're up for that lunch. I'm still not conceding the point but your effort should be rewarded. I have a doctor's appointment in Athens next Thursday morning if you're nearby. DePalma's never disappoints and I'm always up for a Golden Bowl at The Grit, although I do have to admit to a definite weakness for Varsity chili-dogs. I'll treat you to some world class BBQ ribs if you want to drive out to Winder.
R September 28, 2012 at 04:42 pm
But if there’s beef in that Chili, you are contributing to the REDUCTION of methane "generators" out in the field …
You’re indeed going GREEN, in more ways than one.
Dave Ballard September 28, 2012 at 04:52 pm
Let no one say that you were anything if not a true gentleman, Sir. Please check your Patch message board.
I'm looking forward to meeting you.
North Georgia Weather September 29, 2012 at 03:42 am
This was an interesting article, notice the last paragraph.
http://www.foxnews.com/science/2012/09/24/50-million-year-old-redwood-chunk-found-in-diamond-mine/?intcmp=obnetwork
Poptech September 30, 2012 at 01:29 am
Muller was never a skeptic,
http://www.populartechnology.net/2012/06/truth-about-richard-muller.html "If Al Gore reaches more people and convinces the world that global warming is real, even if he does it through exaggeration and distortion - which he does, but he’s very effective at it - then let him fly any plane he wants." - Richard Muller, 2008 "There is a consensus that global warming is real. ...it’s going to get much, much worse." - Richard Muller, 2008 "Let me be clear. My own reading of the literature and study of paleoclimate suggests strongly that carbon dioxide from burning of fossil fuels will prove to be the greatest pollutant of human history. It is likely to have severe and detrimental effects on global climate." - Richard Muller, 2003
Poptech September 30, 2012 at 01:35 am
1. The continuing search for an anthropogenic climate change signal: Limitations of correlation-based approaches
(Geophysical Research Letters, Volume 24, Number 18, pp. 2319–2322, September 1997) - David R. Legates, Robert E. Davis 2. CO2-induced global warming: a skeptic's view of potential climate change (Climate Research, Volume 10, Number 1, pp. 69–82, April 1998) - Sherwood B. Idso 3. Human Contribution to Climate Change Remains Questionable (Eos, Transactions American Geophysical Union, Volume 80, Issue 16, pp. 183-183, April 1999) - S. Fred Singer 4. Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics (International Journal of Modern Physics B, Volume 23, Issue 3, pp. 275-364, January 2009) - Gerhard Gerlich, Ralf D. Tscheuschner 5. Is Global Warming Mainly Due to Anthropogenic Greenhouse Gas Emissions? (Energy Sources, Volume 33, Issue 21, pp. 1985-1992, August 2011) - Xiaobing Zhaoa 6. Scrutinizing the atmospheric greenhouse effect and its climatic impact (Natural Science, Volume 3, Number 12, pp. 971-998, December 2011) - Gerhard Kramm, Ralph Dlugi
Michael k September 30, 2012 at 02:14 am
Dave's blog post is symptomatic of the right's claims that independent research has not overwhelmingly concluded that global warming over the past 50 years is predominantly anthropogenic, i.e. originating in human activity.
That is not to say that independent research has entirely concluded, it has merely overwhelmingly concluded that global warming is occurring and it is mostly the result of human activity. The reason a debate exists is because of industry-funded efforts to cloud the issue. This is similar to the early days of the tobacco industry's efforts to discredit scientific studies on its product's negative health impact. Where would the "No global warming" community be without oil company largesse? The only credible list of scientific skeptics that I have seen is at this Wikipedia page: http://en.wikipedia.org/wiki/List_of_scientists_opposing_the_mainstream_scientific_assessment_of_global_warming

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