The new UN IPCC report is facing even more credibility question after a climate expert found a glaring error in the use of climate data.
Dr. Ross McKitrick wrote on October 11: The “new [UN] IPCC SR15 report relies on Marcott 2013 to contrast recent warming with past 7,000 years. Marcott et al. said their study should not be used for that purpose after critics hammered their poor 20C data quality.”
McKitrick was referring to a 2013 study by Prof. Shaun Marcott of Oregon University, which claimed that current temperatures were the hottest in 4000 years. But the study quickly came under intense scrutiny as many scientists ridiculed the study’s claims and calls for retractions were issued. McKitrick’s 2013 analysis of the study that the current UN report relies upon, was scathing. Marcott’s “11,000-year study’s 20th-century claim is groundless,” McKitrick wrote in 2013.
Marcott’s 2013 study was also accused of “skirting awfully close to crossing the line into research misconduct” and a “gross misrepresentation of the findings.” See: Climate Depot Round Up of Marcott’s Collapsed New Hockey Stick Study — Prof. Pielke Jr. Mocks As The ‘Hockey Stick that never was’
But the new 2018 UN IPCC not only relied on the discredited 2013 Marcott study to gin up climate alarm, but the UN also misused the Marcott study in a way that the authors of that study explicitly warned should not be done.
The UN IPCC has been heavily criticized by former UN scientists and other scientists for its political lobbying tone and gross distortions of science. See: UN IPCC is ‘a purely political body posing as a scientific institution’ & Audit of UN IPCC Finds ‘Careless and Amateur’ Data
The latest IPCC report moved even further to full political advocacy by using suspect statistics and claims to urge the world to “unprecedented changes in all aspects of society.”
McKitrick is a paleoclimate expert and a professor at the University of Guelph and author of numerous peer-reviewed climate studies.
Background:
Ross McKitrick demolishes Marcott hokey stick: 11,000-year study’s 20th-century claim is groundless – ‘The trouble is, as they quietly admitted over the weekend, their new and stunning claim is groundless. The real story is only just emerging, and it isn’t pretty’
Retraction Watch: UK Met Office withdraws article about Marcott’s hockey stick
Climate Audit’s Steve McIntyre: ‘April Fools’ Day for Marcott et al’
Flashback: Climate Audit’s Steve McIntyre keeps digging on new ‘Hockey Stick’ paper: ‘No Uptick in Marcott Thesis’ — ‘I wonder what accounts for the difference’ — Marcott’s thesis has a series of diagrams in an identical style as the Science article. The proxy datasets are identical…the diagrams in the thesis lack the closing uptick of the Science’ — In addition to difference in closing uptick, important reconstruction versions were at negative values in the closing portion of the thesis graphic, while they were at positive values in the closing portion of the Science graphic’
