An article by a grad student of my acquaintance at UT. Quote from another paleoclimate grad student in conversation “the deniers never hate on us the way they do the tree ring people, ’cause our data is solid”. Anyway, the original is here, and Kaustubh (a.k.a “Kow”) retains copyright.
Proxy Evidence for Recent Warming
And finally, we have non-thermometer temperature data from so-called proxies: tree rings, ice cores, lake and ocean sediments, stalagmites. Most of these haven’t shown any warming since 1940!
To put it simply: this is false.
Here, I have compiled a (very short) list of scientific articles (keeping the Manns and the Briffas i.e. tree rings away) where the authors do report recent warming in various proxy data. Ice cores, foraminifera, diatoms, stalagmites, corals and lacustrine & marine sediment cores compose some of the listed proxies. Not only do these different proxies around the world show a pronounced warming in the late 20th century, they are also useful in revealing the fossil fuel signature source of recently accumulating carbon dioxide (the Suess effect, see here and here) in the atmosphere. I will happily provide pdfs of any papers if they are requested and will add your favourite scientific article if suggested in the comments.
- “Recent warming'” ice core evidence from tropical ice cores with emphasis on Central Asia – L. Thompson et al., Global And Planetary Change (1993)
- Recent increase in surface-water stability during warming off California as recorded in marine sediments – A. L. Weinheimer et al., Geology (1999)
- Recent warming in a 500-year palaeotemperature record from varved sediments, Upper Soper Lake, Baffin Island, Canada – K. Hughen et al., The Holocene (2000)
- Climate variability in central China over the last 1270 years revealed by high-resolution stalagmite records – D. E. Paulsen et al., Quaternary Science Reviews (2003)
- Marine sedimentary record of natural environmental variability and recent warming in the Antarctic Peninsula – E. W. Domack et al., Antarctic Research Series (2003)
- Cyclic rapid warming on centennial-scale revealed by a 2650-year stalagmite record of warm season temperature – Tan et al., Geophysical Research Letters (2003)
- El Niño/Southern Oscillation and tropical Pacific climate during the last millennium. – K. Cobb et al., Nature (2003)
- Diatom shifts as evidence for recent Subarctic warming in a remote tundra lake, NWT, Canada – K. Rühland & J. P. Smol, Palaeogeography, Palaeoclimatology, Palaeoecology (2005)
- Planktonic Foraminifera of the California Current Reflect 20th-Century Warming – D. B. Field et al., Science (2006)
- Recent rapid warming trend revealed from the isotopic record in Muztagata ice core, eastern Pamirs – L. Tian et al., Journal of Geophysical Research Atmospheres (2006)
- Rapid 20th century environmental change on northeastern Baffin Island, Arctic Canada inferred from a multi-proxy lacustrine record – E. K. Thomas et al., Journal of Paleolimnology (2007)
- An 8-century tropical Atlantic SST record from the Cariaco Basin: Baseline variability, twentieth-century warming, and Atlantic hurricane frequency – D. Black et al., Paleoceanography (2007)
- Rapid 20th-Century Increase in Coastal Upwelling off Northwest Africa – H. V. McGregor et al., Science (2007)
- High-Resolution Greenland Ice Core Data Show Abrupt Climate Change Happens in Few Years – J. Steffensen et al., Science (2008)
- Unprecedented recent warming of surface temperatures in the Eastern tropical Pacific Ocean – J. Conroy et al., Nature Geoscience (2009)
- Regionally coherent Little Ice Age cooling in the Atlantic Warm Pool – J. Richey et al., Geophysical Research Letters (2009)
- 2,000-year-long temperature and hydrology reconstructions from the Indo-Pacific warm pool – D. Oppo et al., Nature (2009)
- Globorotalia truncatulinoides (dextral) Mg/Ca as a proxy for Gulf of Mexico winter mixed-layer temperature: Evidence from a sediment trap in the northern Gulf of Mexico – J. Spear et al. Marine Micropaleontology (2011)
- Foraminiferal faunal evidence of twentieth-century Barents Sea warming – L. J. Wilson et al., The Holocene (2011)
- Impacts of a recent storm surge on an Arctic delta ecosystem examined in the context of the last millennium – M. Pisaric et al., Proceedings of the National Academy of Sciences (2011)
This is a very small subset of papers where authors report late 20th century warming via non-tree ring proxies. Coincidentally (or not), the marine sediment core that I am currently working on shows a large 20th century warming signal as well. In fact, I would place more trust in proxies than pre-satellite (pre~1950) or reanalysis data in accurately recording temperature and other climatic variables.
Summary: (to reiterate), Dr. Singer’s claim is false.
Pat Frank responds at Watts':
Michael Tobis says, “Since Heartland is happy to pay people to say things about science that just aren’t true,…,” with the link pointing to a blog supposing that Patrick Michaels is so very dead wrong to be skeptical of non-tree-ring temperature proxies.
Well, Michael, presumably you can point us to the physical theory that will extract a physically valid temperature from a diatom shell, or a spleothem, a coral band, a sedimentary varve, or an ice-core ring. Physically valid is not just scale-it-to-a-measurement-trend-and-call-it-temperature statistical hokum. It’s not just we-can-measure-deuterium-and-18-O and never mind about the possible monsoon shifts or rainings out that are hiding behind the curtain. And it’s not just the ad hoc and tendentious assignment of temperature to the PC1 of a proxy qualitatively judged to be temperature limiting.
Where’s the falsifiable physical theory, Mike? Where are the physical equations that will transform a spleothem (ice core ring, coral band, varve, etc.) into a temperature? If you don’t have them (and you don’t), then Patrick Michaels is correct, Heartland is innocent of any wrong-doing, your champion is wrong, and so are you. Proxy so-called temperatures are not physically real. They have no physical meaning.
I am so tired of people who call themselves scientists all the while taking a thoroughly glaringly obviously facile pseudo-science and elevating it to holy writ. What is it with you people, that you hold your professional integrity so cheaply?
[ Kau replies on his blog as follows: ]
Since then, there have been thousands of experiments (laboratory based, culture experiments, sediment traps) to accurately quantify these estimates and to pin down uncertainties – 60 years is a long time! Even though quantitative estimates are refined every now and then due to progress in mass spectrometry and understanding the biology of these creatures, qualitative inference (trends, variability) of foraminiferal proxy records from as far backas the 50s still holds true (Milankovitch cycles, ice ages etc.)
In summary, a measurement in a geological artifact (speleothem isotopes, fossil content, paleosols composition, tree-rings width, ice-core bubble makeup etc.) known to respond to a climatic parameter (temperature, humidity, precipitation, pCO2 etc.) in the present is utilized as a proxy for the past. These proxy measurements are independently verified and statistically validated by robust methods of comparison with instrumental data and should have a sound physical reason as to why they change with aforementioned climate parameter (correlation does not imply causation); only then are proxy reconstructions and their inherent quantitative and qualitative implications accepted by the community. Nobody merely matches trends and principal components of empirical orthogonal functions to a random measurement in an unknown fossil as was accused.
- Thermodynamics & Isotopes
- The Thermodynamic Properties of Isotopic Substances – H. Urey, Journal of the Chemical Society (1947)
- Oxygen isotopes in nature and in the laboratory – H. Urey, Science (1948)
- On the Isotopic Chemistry of Carbonates and a Paleotemperature Scale – J. M. McCrea, Journal of Chemical Physics (1950)
- Foraminiferal δ18O
- Experimental paleotemperature equation for planktonic foraminifera – Erez & Luz, Geochimica Cosmochimica Acta (1983)
- Reevaluation of the oxygen isotopic composition of planktonic foraminifera: Experimental results and revised paleotemperature equations – B. E. Bemis et al., Paleoceanography (1998)
- Foraminiferal Mg/Ca
- Magnesium in tests of Neogloboquadrina pachyderma sinistral from high northern and southern latitudes – D. Nürnberg, Journal of Foraminiferal Research (1995)
- Calibration of Mg/Ca thermometry in planktonic foraminifera from a sediment trap time series – Anand et al., Paleoceanography (2003)
- Coral δ18O
- Coral Skeletal Chemistry: Physiological & Environmental Regulation of Stable Isotopes and Trace Metals in Montastrea annularis – T. J. Goreau, Proceedings of the Royal Society (1977)
- Evaluating climate indices and their geochemical proxies measured in corals – R. G. Fairbanks et al., Coral Reefs (1997)
- Coral Sr/Ca
- Sea-Surface Temperature from Coral Skeletal Strontium/Calcium Ratios – J. W. Beck et al., Science (1992)
- The isotopic geochemistry of speleothems—I. The calculation of the effects of different modes of formation on the isotopic composition of speleothems and their applicability as palaeoclimatic indicators – C. H. Hendy, Geochimica et Cosmochimica Acta (1971)
- Oxygen isotopes in meteoric calcite cements as indicators of continental paleoclimate – P. D. Hays et al., Geology (1991)
- Palaeo-climate reconstruction from stable isotope variations in speleothems: a review – F. McDermott, Quaternary Science Reviews (2004)
|Nobody is more critical of new proxies than paleoclimatologists/paleoceanographers themselves.
Taken from Elderfield, GCA (2002)
Mr Frank continues at Watts:
Michael Tobis, apologies for the Singer-Michaels mix-up.
You wrote, “this is an attack on the whole idea of proxies, which doesn’t directly respond to Singer’s claims that there is no proxy evidence,…
Michael, if the “proxies” are not proxies, then there is no proxy evidence. That’s pretty basic, and if you don’t get that, there’s no point talking further.
You say that, “the corals [produce] credible and globally coherent ENSO records,” but that’s not the point is it. The point is whether corals produce physical temperature records.
Corals respond to, e.g., temperature, precipitation, nutrient flux, and predation. How does anyone extract physically valid degrees centigrade from that? And yet, proxy temperature trends are authoritatively published with ordinates showing resolutions of 0.2 C. Those plots are scientifically meaningless. Worse, they reflect either disingenuousness or incompetence. There is no other choice. And honestly, I don’t think the answer is disingenuousness.
You asked, “Pat, is it your claim that there is no such thing as paleoclimate evidence?” Evidence of what, Michael? Warmer-wetter/cooler-drier? Or degrees centigrade? The degrees may be there, but we won’t know until there’s a physical theory with which to derive them. Or do you deny that?
You asked, “Is it your claim that there is no science without equations reducible to physics?” I claim there is no science without a falsifiable theory. Physics has them. Chemistry has them. Biology has them. Geology has them. Climate modeling does not. Neither does proxy temperature. It’s good to keep your science straight, Michael. And it’s neither naive nor solipsistic to pay attention to what is science and what most assuredly is not. Proxy thermometry is not science.
What MDs do is grounded in Biology. What engineers do is grounded in Physics. Nothing in either profession makes sense without the backing of their foundational science. One might argue empirical rules of thumb, but I promise you won’t make that case.
I’ve argued the proxy case at Steve McIntyre’s CA. Rob Wilson, a proxy professional, took issue. He had no good defense. Neither will your cadre. It’s all just associational arguments decorated with numerical filters and statistical arcana.
Proceed with your digging, Michael. The verdict won’t change.
The referenced discussion at CA contains the following summary from Pat Frank:
Metabolic theory applied to trees certainly predicts temperature limited growth, but not quantitatively. There are no known metrics derived from trees that can be cranked through a biophysical theory to produce a growth temperature.
This quantitative theory plain does not exist, and no statistical methodology can ever produce a physically meaningful metric where there is no physical theory.
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[It's far from clear what that actually means, short of "there is no such thing as a proxy", or "nananana I am not listening".
Some other, somewhat more reasonable, or at least at-first-glance reasonable-sounding complaints from naysayers appear on that CA thread. This one from Eschenbach, for instance, one of the more coherent of the naysayers.
They seem to be obsessed with tree rings over on that thread, though, as is their usual MO.
Those who are new to the climate blogs be warned: any engagement with the tree ring obsession of McIntyre et al is likely to be a bottomless pit. This is the original red herring and they are still flinging it around. My sense is that, like Frank's clueless claim bolded above, it all boils down to denial, pure and simple. But I've never had the patience for it, since in my view tree rings are unimportant.
If someone else wants to write an informed tree ring piece, though, we're interested.