Query: In one particularly damning email, CRU director Phil Jones said he had used ‘Mike’s Nature trick’ to ‘hide the decline’ in temperatures in the second half of the 20th century.

Relevant passages:
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 .

Climatic Research Unit <=SEP=> The Climatic Research Unit ( CRU ) is a component of the University of East Anglia and is one of the leading institutions concerned with the study of natural and anthropogenic climate change .   With a staff of some thirty research scientists and students , the CRU has contributed to the development of a number of the data sets widely used in climate research , including one of the global temperature records used to monitor the state of the climate system , as well as statistical software packages and climate models .

Phil Jones (climatologist) <=SEP=> Philip Douglas Jones ( born April 22 , 1952 ) retired from his positions as the Director of the Climatic Research Unit ( CRU ) and as a Professor in the School of Environmental Sciences at the University of East Anglia ( UEA ) at the end of 2016 . Jones was replaced as CRU director by Tim Osborn and has taken up a position as a Professorial Fellow at the UEA from January 2017 .   His research interests include instrumental climate change , palaeoclimatology , detection of climate change and the extension of riverflow records in the UK . He has also published papers on the temperature record of the past 1000 years .   He is known for maintaining a time series of the instrumental temperature record . This work was featured prominently in both the 2001 and 2007 IPCC reports , where he was a contributing author to Chapter 12 , Detection of Climate Change and Attribution of Causes , of the Third Assessment Report and a Coordinating Lead Author of Chapter 3 , Observations : Surface and Atmospheric Climate Change , of the AR4 .

Climatic Research Unit email controversy <=SEP=> The Climatic Research Unit email controversy ( also known as `` Climategate '' ) began in November 2009 with the hacking of a server at the Climatic Research Unit ( CRU ) at the University of East Anglia ( UEA ) by an external attacker , copying thousands of emails and computer files , the Climatic Research Unit documents , to various internet locations several weeks before the Copenhagen Summit on climate change .   The story was first broken by climate change denialists with columnist James Delingpole popularising the term `` Climategate '' to describe the controversy . Several people considered climate change `` skeptics '' argued that the emails showed global warming was a scientific conspiracy , that scientists manipulated climate data and attempted to suppress critics . The CRU rejected this , saying the emails had been taken out of context and merely reflected an honest exchange of ideas .   The mainstream media picked up the story as negotiations over climate change mitigation began in Copenhagen on 7 December 2009 . Because of the timing , scientists , policy makers and public relations experts said that the release of emails was a smear campaign intended to undermine the climate conference . In response to the controversy , the American Association for the Advancement of Science ( AAAS ) , the American Meteorological Society ( AMS ) and the Union of Concerned Scientists ( UCS ) released statements supporting the scientific consensus that the Earth 's mean surface temperature had been rising for decades , with the AAAS concluding , `` based on multiple lines of scientific evidence that global climate change caused by human activities is now underway ... it is a growing threat to society . ''   Eight committees investigated the allegations and published reports , finding no evidence of fraud or scientific misconduct . However , the reports called on the scientists to avoid any such allegations in the future by taking steps to regain public confidence in their work , for example by opening up access to their supporting data , processing methods and software , and by promptly honouring freedom of information requests . The scientific consensus that global warming is occurring as a result of human activity remained unchanged throughout the investigations .