Sunday, August 30, 2015

36 Hockey Sticks (And Counting)

Thanks to commenter Jack Dale at Roy Spencer's blog, who gave this long and useful list of studies that find a hockey stick from reconstructions of paleoclimate data, compiled by Jim Milks of Seeing the Environmental Forest.

Milks has links to three dozen studies that find a hockey stick, as of 2013. Three dozen. (For links to each specific study, see Milks' post.)

Crowley 2000: 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, et al. 2000: Reconstructed global average temperatures since AD 1500 using temperature data from 616 boreholes from around the globe.

Bertrand et al. 2002: 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 et al. 2002: Reconstructed Northern Hemisphere temperatures between AD 800 and AD 2000 using tree ring chronologies.

Cronin et al. 2003: Reconstructed temperatures between 200 BC and AD 2000 around Chesapeake Bay, USA, using sediment core records.

Pollack and Smerdon 2004: Reconstructed global average temperatures since AD 1500 using temperature data from 695 boreholes from around the globe.

Esper et al. 2005: Compared and averaged five independent reconstructions of Northern Hemisphere temperatures from AD 1000 to AD 2000.

Moberg et al. 2005: 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 2005: Reconstructed global temperatures from AD 1500 to AD 2000 using 169 glacial ice proxies from around the globe.
Rutherford, et al. 2005: 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 et al. 2006: 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 and Briffa 2006: 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 et al. 2007: 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 et al. 2007: Combined multiple older reconstructions into a meta-analysis. Also used existing proxies to calculate a new Northern Hemisphere temperature reconstruction.

Wahl and Ammann 2007: 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, et al. 2007: 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 et al. 2008: 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, et al. 2009: Used tree rings, lake sediment cores, and glacial ice cores to reconstruct Arctic temperatures between 1 BC and 2000 AD.

von Storch et al. 2009: Tested three different temperature reconstruction techniques to show that the Composite plus Scaling method was better than the other two methods.

Frank et al. 2010: A brief history of proxy temperature reconstructions, as well as analysis of the main questions remaining in temperature reconstructions.

Kellerhals et al. 2010: Used ammonium concentration in a glacial ice core to reconstruct tropical South American temperatures over the past 1,600 years.

Ljungqvist 2010: Reconstructed extra-tropical Northern Hemisphere temperatures from AD 1 to AD 2000 using historical records, sediment cores, tree rings, and stalagmites.

Thibodeau et al. 2010: Reconstructed temperatures at the bottom of the Gulf of St. Lawrence since AD 1000 via sediment cores.

Tingley and Huybers 2010a, 2010b: Used a Bayesian approach to reconstruct North American temperatures.

Büntgen et al. 2011: Used tree ring proxies to reconstruct Central European temperatures between 500 BC and AD 2000.

Kemp et al. 2011: 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 et al. 2011: 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.

Martin-Chivelet et al. 2011: Reconstructed temperatures in the Iberian Peninsula from 2000 BC to AD 2000 using stalagmites.
Spielhagen et al. 2011: 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 et al. 2012: Reanalyzed tree ring data for the Torneträsk region of northern Sweden.

Abram et al. 2013: Reconstructed snow melt records and temperatures in the Antarctic Peninsula since AD 1000 using ice core records.

Marcott, et al. 2013: Reconstructed global temperatures over the past 11,000 years using sediment cores. Data ended at AD 1940.

PAGES 2k Consortium 2013: Used multiple proxies (tree rings, sediment cores, ice cores, stalagmites, pollen, etc) to reconstruct regional and global temperatures since AD 1.

Rhodes et al. 2013: Used proxy and instrumental records to reconstruct global temperatures from AD 1753 to AD 2011.

Again, this is hardly surprising. What would be surprising is if any studies found something other than a hockey stick.

As Jim wrote,
The proper response to someone who asserts that the Hockey Stick has been falsified is to ask "Which one?" 
Thanks Jim.

Added -- and more:

Y Zhang et al. 2014: "Millennial minimum temperature variations in the Qilian Mountains, China: evidence from tree rings," Climate of the Past, 10, 1763–1778, 2014.

Shi et al. 2015: "A multi-proxy reconstruction of spatial and temporal variations in Asian summer temperatures over the last millennium," Climate Change, August 2015, Volume 131, Issue 4, pp 663-676. [PDF]


Dano said...

Gus Speth, in his The Bridge at the Edge of the World: Capitalism, the Environment, and Crossing from Crisis to Sustainability uses the hockey stick metaphor throughout the book, including IIRC as an icon at the end of the chapters. The beginning of the book has a graphic with maybe 24, from many different disciplines. I say IIRC because it is not on the shelf where it should be...



Dano said...

This sort of thing (pp 17-18) was what i had in mind.



Unknown said...

Jim Milks at also has a link to NOAA Paleoclimate, which has (inter alia) many of the data sets for temperature reconstructions; and also a link to the data from Marcott et al 2013 at the Science magazine website.

Layzej said...

Anonymous said...

I notice that Andrew Montford has a new post mocking you because one of the papers (Ljungqvist 2010) has a hockey stick that doesn't really look like a hockey stick. IMO, what it really shows is that Andrew Montford is a pedantic idiot. What's maybe more instructive is that noone (I think) has yet pointed out that this is for NH extra-tropics (90N - 30N) only. More amusingly, though, the paper explicitly says

This amplitude is considerably larger than that in the pioneering reconstructions (e.g. Jones et al. 1998; Mann et al. 1999; Crowley and Lowery 2000) which were hampered by a very limited and unevenly dis- tributed set of proxy data.

David Appell said...

ATTP: Thanks for the heads up.

Anonymous said...

I'm impressed that you're trying to engage on Bishop Hill. I used to, but gave up. There's a level of nastiness, dishonesty, and stupidity that even I'm not willing to put up with. I also regard myself as quite tolerant :-)

mikep said...

And calling people who point out that some of the hockeysticks are not hockeystick shaped a pedantic idiot is not nasty or stupid?

Anonymous said...

You're interested in my views are you? Okay, here goes. In my opinion, Andrew Montford is either dishonest or stupid or - quite possibly - both. I'm more than happy to state that publicly and - if the opportunity ever arises - to his face. I think what he promotes on his blog is ridiculous and what he allows in the comments is appalling. The idea that someone who allows such drivel can complain about being called an idiot is just ridiculous.

Now, of course, he's more than welcome to simply ignore my view (as he almost certainly will) but that's no reason for me not to hold it. If, however, it bothers him at all, he can always think about whether or not he is being honest and whether or not what he promotes on his blog makes him look like an idiot (as it almost certainly does to anyone who understands this topic). I don't particularly care either way.

There we go. Happy now?

Tom C said...

Appell -

You are the one who portrayed Ljungqvist as a global T hockey stick. You should be the one embarrassed by the fact that it was not global and not a hockey stick.

Anonymous said...

You are the one who portrayed Ljungqvist as a global T hockey stick.
No he didn't. Try reading this post again with both your eyes - and you mind - open. Also, the original hockey stick (MBH98) only went back to 1400. Try doing a proper comparison with Ljungqvist.