Dr. Fred Singer visited the UT campus last week and gave a talk containing the usual climate denial yarns and I hear, most artfully (not!) dodged scientific questions. I wish I could've attended but unfortunately, I had a class at the same time. This post was motivated by the following claim of his in a WUWT post (in retaliation to the BEST results being publicized and unfavorable to his interests) which he rehashed in the talk as well:
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.
Proxy evidence for recent warming:
- "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 cores 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: Dr. Singer's claim is false.