Query: Ljungqvist's millennial temperature reconstruction was very similar to Moberg et al.

Relevant passages:
List of large-scale temperature reconstructions of the last 2,000 years <=SEP=> This list of large scale temperature reconstructions of the last 2,000 years includes climate reconstructions which have contributed significantly to the modern consensus on the temperature record of the past 2000 years .   The instrumental temperature record only covers the last 150 years at a hemispheric or global scale , and reconstructions of earlier periods are based on climate proxies . In an early attempt to show that climate had changed , Hubert Lamb 's 1965 paper generalised from temperature records of central England together with historical , botanical and archeological evidence to produce a qualitative estimate of temperatures in the north Atlantic region . Subsequent quantitative reconstructions used statistical techniques with various climate proxies to produce larger scale reconstructions . Tree ring proxies can give an annual resolution of extratropical regions of the northern hemisphere , and can be statistically combined with other sparser proxies to produce multiproxy hemispherical or global reconstructions .   Quantitative reconstructions have consistently shown earlier temperatures below the temperature levels reached in the late 20th century . This pattern as seen in was dubbed the hockey stick graph , and as of 2010 this broad conclusion was supported by more than two dozen reconstructions , using various statistical methods and combinations of proxy records , with variations in how flat the pre-20th century `` shaft '' appears .

Hockey stick controversy <=SEP=> In the hockey stick controversy , the data and methods used in reconstructions of the temperature record of the past 1000 years have been disputed . Reconstructions have consistently shown that the rise in the instrumental temperature record of the past 150 years is not matched in earlier centuries , and the name `` hockey stick graph '' was coined for figures showing a long-term decline followed by an abrupt rise in temperatures . These graphs were publicised to explain the scientific findings of climatology , and in addition to scientific debate over the reconstructions , they have been the topic of political dispute . The issue is part of the global warming controversy and has been one focus of political responses to reports by the Intergovernmental Panel on Climate Change ( IPCC ) . Arguments over the reconstructions have been taken up by fossil fuel industry funded lobbying groups attempting to cast doubt on climate science .   The use of proxy indicators to get quantitative estimates of the temperature record of past centuries was developed from the 1990s onwards , and found indications that recent warming was exceptional . The reconstruction introduced the `` Composite Plus Scaling '' ( CPS ) method used by most later large-scale reconstructions , and its findings were disputed by Patrick Michaels at the United States House Committee on Science .   In 1998 , Michael E. Mann , Raymond S. Bradley and Malcolm K. Hughes developed new statistical techniques to produce ( MBH98 ) , the first eigenvector-based climate field reconstruction ( CFR ) . This showed global patterns of annual surface temperature , and included a graph of average hemispheric temperatures back to 1400 . In ( MBH99 ) the methodology was extended back to 1000 . The term hockey stick was coined by the climatologist Jerry D. Mahlman , to describe the pattern this showed , envisaging a graph that is relatively flat to 1900 as forming an ice hockey stick 's `` shaft '' , followed by a sharp increase corresponding to the `` blade '' .  A version of this graph was featured prominently in the 2001 IPCC Third Assessment Report ( TAR ) , along with four other reconstructions supporting the same conclusion . The graph was publicised , and became a focus of dispute for those opposed to the strengthening scientific consensus that late 20th-century warmth was exceptional .   Those disputing the graph included Pat Michaels , the George C. Marshall Institute and Fred Singer . A paper by Willie Soon and Sallie Baliunas claiming greater medieval warmth was used by the Bush administration chief of staff Philip Cooney to justify altering the first Environmental Protection Agency Report on the Environment . The paper was quickly dismissed by scientists in the Soon and Baliunas controversy , but on July 28 , Republican Jim Inhofe spoke in the Senate citing it to claim `` that man-made global warming is the greatest hoax ever perpetrated on the American people '' .   Later in 2003 , a paper by Steve McIntyre and Ross McKitrick disputing the data used in MBH98 paper was publicised by the George C. Marshall Institute and the Competitive Enterprise Institute . In 2004 , Hans von Storch published criticism of the statistical techniques as tending to underplay variations in earlier parts of the graph , though this was disputed and he later accepted that the effect was very small . In 2005 , McIntyre and McKitrick published criticisms of the principal component analysis methodology as used in MBH98 and MBH99 . The analysis therein was subsequently disputed by published papers , including and , which pointed to errors in the McIntyre and McKitrick methodology . In June 2005 , Rep. Joe Barton launched what Sherwood Boehlert , chairman of the House Science Committee , called a `` misguided and illegitimate investigation '' into the data , methods and personal information of Mann , Bradley and Hughes . At Boehlert 's request , a panel of scientists convened by the National Research Council was set up , which reported in 2006 , supporting Mann 's findings with some qualifications , including agreeing that there were some statistical failings but these had little effect on the result . Barton and U.S. Rep. Ed Whitfield requested Edward Wegman to set up a team of statisticians to investigate , and they supported McIntyre and McKitrick 's view that there were statistical failings , although they did not quantify whether there was any significant effect . They also produced an extensive network analysis which has been discredited by expert opinion and found to have issues of plagiarism . Arguments against the MBH studies were reintroduced as part of the Climatic Research Unit email controversy , but dismissed by eight independent investigations .   More than two dozen reconstructions , using various statistical methods and combinations of proxy records , have supported the broad consensus shown in the original 1998 hockey-stick graph , with variations in how flat the pre-20th century `` shaft '' appears . The 2007 IPCC Fourth Assessment Report cited 14 reconstructions , 10 of which covered 1,000 years or longer , to support its strengthened conclusion that it was likely that Northern Hemisphere temperatures during the 20th century were the highest in at least the past 1,300 years . Over a dozen subsequent reconstructions , including Mann et al. 2008 and , have supported these general conclusions .

Hockey stick graph <=SEP=> Hockey stick graphs present the global or hemispherical mean temperature record of the past 500 to 2000 years as shown by quantitative climate reconstructions based on climate proxy records . These reconstructions have consistently shown a slow long term cooling trend changing into relatively rapid warming in the 20th century , with the instrumental temperature record by 2000 exceeding earlier temperatures .   The term `` hockey stick graph '' was coined by the climatologist Jerry Mahlman , to describe the pattern shown by the ( MBH99 ) reconstruction , envisaging a graph that is relatively flat with a downward trend to 1900 as forming an ice hockey stick 's `` shaft '' followed by a sharp , steady increase corresponding to the `` blade '' portion . The reconstructions have featured in Intergovernmental Panel on Climate Change ( IPCC ) reports as evidence of global warming . Arguments over the reconstructions have been taken up by fossil fuel industry funded lobbying groups attempting to cast doubt on climate science .   Paleoclimatology dates back to the 19th century , and the concept of examining varves in lake beds and tree rings to track local climatic changes was suggested in the 1930s . In the 1960s , Hubert Lamb generalised from historical documents and temperature records of central England to propose a Medieval Warm Period from around 900 to 1300 , followed by Little Ice Age . This was the basis of a `` schematic diagram '' featured in the IPCC First Assessment Report of 1990 beside cautions that the medieval warming might not have been global . The use of indicators to get quantitative estimates of the temperature record of past centuries was developed , and by the late 1990s a number of competing teams of climatologists found indications that recent warming was exceptional . introduced the `` Composite Plus Scaling '' ( CPS ) method used by most later large scale reconstructions . Their study was featured in the IPCC Second Assessment Report of 1995 .   In 1998 Michael E. Mann , Raymond S. Bradley and Malcolm K. Hughes developed new statistical techniques to produce ( MBH98 ) , the first eigenvector-based climate field reconstruction ( CFR ) . This showed global patterns of annual surface temperature , and included a graph of average hemispheric temperatures back to 1400 with shading emphasising that uncertainties ( to two standard error limits ) were much greater in earlier centuries . independently produced a CPS reconstruction extending back for a thousand years , and ( MBH99 ) used the MBH98 methodology to extend their study back to 1000 .   A version of the MBH99 graph was featured prominently in the 2001 IPCC Third Assessment Report ( TAR ) , which also drew on Jones et al. 1998 and three other reconstructions to support the conclusion that , in the Northern Hemisphere , the 1990s was likely to have been the warmest decade and 1998 the warmest year during the past 1,000 years . The graph became a focus of dispute for those opposed to the strengthening scientific consensus that late 20th century warmth was exceptional . In 2003 , as lobbying over the 1997 Kyoto Protocol intensified , a paper claiming greater medieval warmth was quickly dismissed by scientists in the Soon and Baliunas controversy . Later in 2003 , Stephen McIntyre and Ross McKitrick published disputing the data used in MBH98 paper . In 2004 Hans von Storch published criticism of the statistical techniques as tending to underplay variations in earlier parts of the graph , though this was disputed and he later accepted that the effect was very small . In 2005 McIntyre and McKitrick published criticisms of the principal components analysis methodology as used in MBH98 and MBH99 . Their analysis was subsequently disputed by published papers including and which pointed to errors in the McIntyre and McKitrick methodology . Political disputes led to the formation of a panel of scientists convened by the National Research Council , their North Report in 2006 supported Mann 's findings with some qualifications , including agreeing that there were some statistical failings but these had little effect on the result .   More than two dozen reconstructions , using various statistical methods and combinations of proxy records , support the broad consensus shown in the original 1998 hockey-stick graph , with variations in how flat the pre-20th century `` shaft '' appears . The 2007 IPCC Fourth Assessment Report cited 14 reconstructions , 10 of which covered 1,000 years or longer , to support its strengthened conclusion that it was likely that Northern Hemisphere temperatures during the 20th century were the highest in at least the past 1,300 years . Further reconstructions , including Mann et al. 2008 and , have supported these general conclusions .

North Report <=SEP=> The North Report was a 2006 report evaluating reconstructions of the temperature record of the past two millennia , providing an overview of the state of the science and the implications for understanding of global warming . It was produced by a National Research Council committee , chaired by Gerald North , at the request of Representative Sherwood Boehlert as chairman of the U.S. House of Representatives Committee on Science .   These reconstructions had been dubbed `` hockey stick graphs '' after the 1999 reconstruction by Mann , Bradley and Hughes ( MBH99 ) , which used the methodology of their 1998 reconstruction covering 600 years ( MBH98 ) . A graph based on MBH99 was featured prominently in the 2001 IPCC Third Assessment Report ( TAR ) , and became a focus of the global warming controversy over the 1997 Kyoto Protocol . It was disputed by various contrarians , and in the politicisation of this hockey stick controversy the New York Times of 14 February 2005 hailed a paper by businessman Stephen McIntyre and economist Ross McKitrick ( MM05 ) as undermining the scientific consensus behind the Kyoto agreement . On 23 June 2005 , Rep. Joe Barton , chairman of the House Committee on Energy and Commerce , with Ed Whitfield , Chairman of the Subcommittee on Oversight and Investigations , wrote joint letters referring to issues raised by the Wall Street Journal article , and demanding that Mann , Bradley and Hughes provide full records on their data and methods , finances and careers , information about grants provided to the institutions they had worked for , and the exact computer codes used to generate their results . Boehlert said this was a `` misguided and illegitimate investigation '' into something that should properly be under the jurisdiction of the Science Committee , and in November 2005 after Barton dismissed the offer of an independent investigation organised by the U.S. National Academy of Sciences , Boehlert requested the review , which became the North Report .   The North Report went through a rigorous review process , and was published on 22 June 2006 . It concluded `` with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries '' , justified by consistent evidence from a wide variety of geographically diverse proxies , but `` Less confidence can be placed in large-scale surface temperature reconstructions for the period from 900 to 1600 '' . It broadly agreed with the basic findings of the original MBH studies , which subsequently been supported by other reconstructions and proxy records , while emphasising uncertainties over earlier periods . The principal component analysis methodology that McIntyre and McKitrick had contested had a small tendency to bias results so was not recommended -- but it had little influence on the final reconstructions , and other methods produced similar results .