WASHINGTON • A former National Oceanic and Atmospheric Administration (NOAA) scientist has reopened a contentious debate over the validity of a key climate change study by the US agency, asserting that procedures for data archiving were not followed by its authors.
The claims by Mr John Bates, first published in the Mail On Sunday and later amplified in a blog post he authored, have prompted Mr Lamar Smith, Republican representative for Texas and chairman of the House Committee on Science, Space and Technology, to criticise NOAA senior officials for "playing fast and loose with the data in order to meet a politically predetermined conclusion".
But many scientists, although hesitant to pronounce on the specific charges about data archiving, have pointed out that the research has been independently confirmed by another recent study - and that in any case, none of this raises any significant doubt about human- caused climate change.
Meanwhile, the researchers behind the original NOAA paper have disagreed strongly with Mr Bates' charges, as has at least one scientist who worked with the team.
At issue is a 2015 bombshell report from scientists with NOAA's National Centres for Environmental Information (NCEI), led by its then director Tom Karl. The paper, published in the leading journal Science, addressed a favourite argument from the climate-doubting camp - the idea that temperature records indicate a slowdown or "pause" in global warming from 1998 on into the 21st century.
The Karl paper seemed to lay these arguments to rest by using updated temperature data sets to demonstrate that no pause has occurred and that recent temperature patterns remain in line with the long-term warming trend.
The paper caused an immediate firestorm among conservatives upon its publication, prompting Mr Smith to issue a congressional subpoena to the NOAA administrator aimed at investigating the adjustments the researchers had made to the historical data sets.
Mr Bates is a long-time NOAA researcher who, before retiring last year, was a principal scientist at NCEI. His charges have instantly fed into a bitter debate that has been playing out over the timing of the release of the NOAA report and its conclusion, challenging a central assertion of those who are sceptical of global warming.
Mr Bates' claims are outlined in a guest blog post, which he published on former Georgia Tech climate scientist Judith Curry's blog over the weekend. Many are highly technical in nature.
In essence, Mr Bates asserts that the paper's authors failed to comply with certain NOAA policies involving the managing and archiving of climate data, and that the study's results cannot be replicated or verified as a result. He also raises concerns about some of the software used in the study's data processing, including issues involving coding errors and certain procedural issues surrounding the development and use of the programs.
And Mr Bates implies that the authors manipulated their data to place a greater emphasis on global warming and rushed the paper's publication to coincide with the 2015 United Nations climate conference, which ultimately led to the adoption of the Paris climate agreement. The implication has been rejected by the authors.
But in the few days since the blog post and news reports were released, multiple climate scientists - both involved and uninvolved with the research in question - have come forward to combat these claims. They observe that even if there were procedural issues involved with the management of the data sets used, the data itself as well as the study's results appear to be sound. And they have already been independently verified by at least one other research group. More importantly, each response defends the scientific integrity of the study.