One of the persistent denier myths is that the Hockey Stick (usually meaning Mann, M. E., R. S, Bradley, and M. K. Hughes. 1999. Northern Hemispheric Temperatures During the Past Millenium: Inferences, Uncertainties, and Limitations. Geophysical Research Letters. 26:759-762) has been discredited. Not only is that myth false but Mann et al. (1999) has been validated through the publication of numerous hockey stick graphs since 1999. Here is a brief list of the ones I know:
Crowley, T. J. 2000. Causes of Climate Change Over the Past 1000 Years. Science 289:270-277: Used both his own and Mann et al. (1999)'s hockey sticks to examine the cause of temperature changes over the past 1,000 years. Found that natural forcings could not explain twentieth century warming without the effect of greenhouse gases.
Huang, S, H. N. Pollack, and P. Shen. 2000. Temperature Trends over the past five centuries reconstructed from borehole temperatures. Nature 403:756-758: Reconstructed global average temperatures since AD 1500 using temperature data from 616 boreholes from around the globe.
Bertrand, C., M. Loutre, M. Crucifix, and A. Berger. 2002. Climate of the Last Millenium: A Sensitivity Study. Tellus 54A:221-244.: Reconstructed solar output, volcanic activity, land use changes, and greenhouse gas concentrations since AD 1000, then computed the expected temperature changes due to those forcings. Compared the computed temperature changes with two independent temperature reconstructions.
Esper, J., E. R. Cook, and F. H. Schweingruber. 2002. Low-frequency Signals in Long Tree-ring Chronologies for Reconstructing Past Temperature Variability. Science 295:2250-2253: Reconstructed Northern Hemisphere temperatures between AD 800 and AD 2000 using tree ring chronologies.
Cronin, T. M., G. S. Dwyer, T. Kamiya, S. Schwede, and D. A. Willard. 2003. Medieval Warm Period, Little Ice Age and 20th Century Temperature Variability from Chesapeake Bay. Global and Planetary Change 36: 17-29: Reconstructed temperatures between 200 BC and AD 2000 around Chesapeake Bay, USA, using sediment core records.
Pollack, H. N. and J. E. Smerdon. 2004. Borehole Climate Reconstructions: Spatial Structure and Hemispheric Averages. Journal of Geophysical Research 109:D11106: Reconstructed global average temperatures since AD 1500 using temperature data from 695 boreholes from around the globe.
Esper, J., R. J. S. Wilson, D. C. Frank, A. Moberg, H. Wanner, and J. Luterbacher. 2005. Climate: Past Ranges and Future Changes. Quarternary Science Reviews 24:2164-2166: Compared and averaged five independent reconstructions of Northern Hemisphere temperatures from AD 1000 to AD 2000.
Moberg, A., D. M. Sonechkin, K. Holmgren, N. M. Datsenko, and W. Karlen. 2005. Highly Variable Northern Hemisphere Temperatures Reconstructed from Low- and High-resolution Proxy Data. Nature 433:613-617: Combined tree ring proxies with glacial ice cores, stalagmite, and lake sediment proxies to reconstruct Northern Hemisphere temperatures from AD 1 to AD 2000.
Oerlemans, J. 2005. Extracting a Climate Signal from 169 Glacier Records. Science 308:675-677: Reconstructed global temperatures from AD 1500 to AD 2000 using 169 glacial ice proxies from around the globe.
Rutherford, S., M. E. Mann, T. J. Osborn, R. S. Bradley, K. R. Briffa, M. K. Hughes, and P. D. Jones. 2005. Proxy-based Northern Hemisphere Surface Temperature Reconstructions: Sensitivity to Method, Predictor Network, Target Season, and Target Domain. Journal of Climate 18:2308-2329: Compared two multi-proxy temperature reconstructions and tested the results of each reconstruction for sensitivity to type of statistics used, proxy characteristics, seasonal variation, and geographic location. Concluded that the reconstructions were robust to various sources of error.
D'Arrigo, R. R. Wilson, and G. Jacoby. 2006. On the Long-term Context for Late Twentieth Century Warming. Journal of Geophysical Research 111:D03103: Reconstructed Northern Hemisphere temperatures between AD 700 and AD 2000 from multiple tree ring proxies using a new statistical technique called Regional Curve Standardization. Concluded that their new technique was superior to the older technique used by previous reconstructions.
Osborn, T. J. and K. R. Briffa. 2006. The Spatial Extent of 20th-century Warmth in the Context of the Past 1200 Years. Science 841-844: Used 14 regional temperature reconstructions between AD 800 and AD 2000 to compare spatial extent of changes in Northern Hemisphere temperatures. Found that twentieth century warming was more widespread than any other temperature change of the past 1,200 years.
Hegerl, G. C., T. J. Crowley, M. Allen, W. T. Hyde, H. N. Pollack, J. Smerdon, and E. Zorita. 2007. Detection of Human Influence on a New, Validated 1500-year Temperature Reconstruction. Journal of Climate 20:650-666: Combined borehole temperatures and tree ring proxies to reconstruct Northern Hemisphere temperatures over the past 1,450 years. Introduced a new calibration technique between proxy temperatures and instrumental temperatures.
Juckes, M. N., M. R. Allen, K. R. Briffa, J. Esper, G. C. Hegerl, A. Moberg, T. J. Osborn, and S. L. Weber. 2007. Millenial Temperature Reconstruction Intercomparison and Evaluation. Climate of the Past 3:591-609: Combined multiple older reconstructions into a meta-analysis. Also used existing proxies to calculate a new Northern Hemisphere temperature reconstruction.
Wahl, E. R. and C. M. Ammann. 2007. Robustness of the Mann, Bradley, Hughes Reconstruction of Northern Hemisphere Surface Temperatures: Examination of Criticisms Based on the Nature and Processing of Proxy Climate Evidence. Climatic Change 85:33-69: Used the tree ring proxies, glacial proxies, and borehole proxies used by Mann et al. (1998, 1999) to recalculate Northern Hemisphere temperatures since AD 800. Refuted the McIntyre and McKitrick criticisms and showed that those criticisms were based on flawed statistical techniques.
Wilson, R., R. D'Arrigo, B. Buckley, U. Büntgen, J. Esper, D. Frank, B. Luckman, S. Payette, R. Vose, and D. Youngblut. 2007. A Matter of Divergence: Tracking Recent Warming at Hemispheric Scales Using Tree Ring Data. Journal of Geophysical Research 112:D17103: Reconstructed Northern Hemisphere temperatures from AD 1750 to AD 2000 using tree ring proxies that did not show a divergence problem after AD 1960.
Mann, M. E., Z. Zhang, M. K. Hughes, R. S. Bradley, S. K. Miller, S. Rutherford, and F. Ni. 2008. Proxy-based Reconstructions of Hemispheric and Global Surface Temperature Variations over the Past Two Millenium. Proceedings of the National Academy of Sciences 105:13252-13257: Reconstructed global temperatures between AD 200 and AD 2000 using 1,209 independent proxies ranging from tree rings to boreholes to sediment cores to stalagmite cores to Greenland and Antarctic ice cores.
Kaufman, D. S., D. P. Schneider, N. P. McKay, C. M. Ammann, R. S. Bradley, K. R. Briffa, G. H. Miller, B. L. Otto-Bliesner, J. T. Overpeck, B. M. Vinther, and Arctic Lakes 2k Project Members. 2009. Recent Warming Reverses Long-term Arctic Cooling. Science 325:1236-1239: Used tree rings, lake sediment cores, and glacial ice cores to reconstruct Arctic temperatures between 1 BC and 2000 AD.
von Storch, H., E. Zorita, and F. González-Rouco. 2009. Assessment of Three Temperature Reconstruction Methods in the Virtual Reality of a Climate Simulation. International Journal of Earth Science 98:67-82: Tested three different temperature reconstruction techniques to show that the Composite plus Scaling method was better than the other two methods.
Frank, D., J. Esper, E. Zorita, and R. Wilson. 2010. A Noodle, Hockey Stick, and Spaghetti Plate: A Perspective on High-resolution Paleoclimatology. Climate Change 1:507-516: A brief history of proxy temperature reconstructions, as well as analysis of the main questions remaining in temperature reconstructions.
Kellerhals, T., S. Brütsch, M. Sigl, S. Knüsel, H. W. Gäggeler, and M. Schwikowski. 2010. Ammonium Concentration in Ice Cores: A New Proxy for Regional Reconstruction? Journal of Geophysical Research 115:D16123: Used ammonium concentration in a glacial ice core to reconstruct tropical South American temperatures over the past 1,600 years.
Ljungqvist, F. C. 2010. A New Reconstruction of Temperature Variability in the Extra-tropical Northern Hemisphere During the Last Two Millenia. Geografiska Annaler: Series A Physical Geography 92:339-351 : Reconstructed extra-tropical Northern Hemisphere temperatures from AD 1 to AD 2000 using historical records, sediment cores, tree rings, and stalagmites.
Thibodeau, B., A. de Vernal, C. Hillaire-Marcel, and A. Mucci. 2010. Twentieth Century Warming in Deep Waters of the Gulf of St. Lawrence: A Unique Feature of the Last Millenium. Geophysical Research Letters 37:L17604: Reconstructed temperatures at the bottom of the Gulf of St. Lawrence since AD 1000 via sediment cores.
Tingley, M. P. and P. Huybers. 2010. A Bayesian Algorithm for Reconstructing Climate Anomalies in Space and Time. Part I: Development and Application to Paleoclimate Reconstruction Problems. Journal of Climate 23:2759-2781.
Tingley, M. P. and P. Huybers. 2010. A Bayesian Algorithm for Reconstructing Climate Anomalies in Space and Time. Part II: Comparison with the Regularized Expectation Maximum Algorithm. Journal of Climate 23:2782-2800. Both Tingley and Huybers papers revolved around the same reconstruction, in which they derived and used a Bayesian approach to reconstruct North American temperatures.
Büntgen, U., W. Tegel, K. Nicolussi, M. McCormick, D. Frank, V. Trouet, J. O. Kaplan, F. Herzig, K. Heussner, H. Wanner, J. Luterbacher, and J. Esper. 2011. 2500 Years of European Climate Variability and Human Susceptibility. Science 331:578-582: Used tree ring proxies to reconstruct Central European temperatures between 500 BC and AD 2000.
Kemp, A. C., B. P. Horton, J. P. Donnelly, M. E. Mann, M. Vermeer, and S. Rahmstorf. 2011. Climate Related Sea-level Variations Over the Past Two Millenia. Proceedings of the National Academy of Sciences 108:11017-11022: Reconstructed sea levels off North Carolina, USA from 100 BC to AD 2000 using sediment cores. They also showed that sea levels changed with global temperature for at least the past millennium.
Kinnard, C. C. M. Zdanowicz, D. A. Fisher, E. Isaksson, A. de Vernal, and L. G. Thompson. 2011. Reconstructed Changes in Arctic Sea Ice Over the Past 1,450 Years. Nature 479:509-512: Used multiple proxies to reconstruct late summer Arctic sea ice between AD 561 and AD 1995, using instrumental data to extend their record to AD 2000.
Martín-Chivelet, J., M. B. Muñoz-García, R. L. Edwards, M. J. Turrero, and A. L. Ortega. 2011. Land Surface Temperature Changes in Northern Iberia Since 4000 yr BP, Based on δ13C of Speleothems. Global and Planetary Change 77:1-12: Reconstructed temperatures in the Iberian Peninsula from 2000 BC to AD 2000 using stalagmites.
Spielhagen, R. F., K. Werner, S. A. Sørensen, K. Zamelczyk, E. Kandiano, G. Budeus, K. Husum, T. M. Marchitto, and M. Hald. 2011. Enhanced Modern Heat Transfer to the Arctic by Warm Atlantic Water. Science 331:450-453 : Reconstructed marine temperatures in the Fram Strait from 100 BC to AD 2000 using sediment cores.
Esper et al. 2012: Used tree ring proxies to reconstruct Northern Scandinavian temperatures 100 BC to AD 2000. May have solved the post-AD 1960 tree ring divergence problem.
Ljungqvist et al. 2012: Used a network of 120 tree ring proxies, ice core proxies, pollen records, sediment cores, and historical documents to reconstruct Northern Hemisphere temperatures between AD 800 and AD 2000, with emphasis on proxies recording the Medieval Warm Period.
Melvin, T. M., H. Grudd, and K. R. Briffa. 2012. Potential Bias in 'Updating' Tree-ring Chronologies Using Regional Curve Standardisation: Re-processing 1500 Years of Torneträsk Density and Ring-width Data. The Holocene 23:364-373: Reanalyzed tree ring data for the Torneträsk region of northern Sweden.
Abram, N. J., R. Mulvaney, E. W. Wolff, J. Triest, S. Kipfstuhl, L. D. Trusel, F. Vimeux, L. Fleet, and C. Arrowsmith. 2013. Acceleration of Snow Melt in an Antarctic Peninsula Ice Core During the Twentieth Century. Nature Geoscience 6:404-411: Reconstructed snow melt records and temperatures in the Antarctic Peninsula since AD 1000 using ice core records.
Marcott, S. A., J. D. Shakun, P. U. Clark, and A. C. Mix. 2013. A Reconstruction of Regional and Global Temperature for the Past 11,300 Years. Science 339:1198-1201: Reconstructed global temperatures over the past 11,000 years using sediment cores. Data ended at AD 1940.
PAGES 2k Consortium. 2013. Continental-scale Temperature Variability During the Past Two Millennia. Nature Geoscience 6:339-346: Used multiple proxies (tree rings, sediment cores, ice cores, stalagmites, pollen, etc) to reconstruct regional and global temperatures since AD 1.
Rohde, R., R. A. Muller, R. Jacobsen, E. Muller, S. Perimutter, A. Rosenfeld, J. Wurtele, D. Groom, and C. Wickham. 2013. A New Estimate of the Average Earth Surface Land Temperature Spanning 1753 to 2011. Geoinformatics and Geostatistics: An Overview 1:1-7: Used proxy and instrumental records to reconstruct global temperatures from AD 1753 to AD 2011.
Wilson, R., K. Anchukaitis, K. R. Briffa, U. Büntgen, E. Cook, R. D'Arrigo, N. Davi, J. Esper, D. Frank, B. Gunnarson, G. Hegerl, S. Helama, S. Klesse, P. J. Krusic, H. W. Linderholm, V. Myglan, T. J. Osborn, M. Rydval, L. Schneider, A. Schurer, G. Wiles, P. Zhang, and E. Zorita. 2016. Last Millennium Northern Hemisphere Summer Temperatures from Tree rings: Part I: The Long Term Context. Quarternary Science Reviews 134:1-18. Introduces and details the new N-TREND2015 temperature reconstruction using 54 proxy records.
The proper response to someone who asserts that the Hockey Stick has been falsified is to ask "Which one?" As for what most of the temperature reconstructions show, the data from Marcott et al. (2013) combined with 30-year smoothed HadCRUT4 data is fairly representative:
Update: I've posted two lengthy responses rebutting "Anonymous" in the comments. Quite frankly, none of "his" numerous claims stand up to scrutiny. Part 1, Part 2.