Rep. Lamar Smith (R-TX) is back with more accusations against National Oceanic and Atmospheric Administration (NOAA) climate scientists. The new claims came in the form of another letter sent to Commerce Secretary Penny Pritzker on Wednesday.

The letter alleges for the first time, that “information provided to the [House Committee on Science, Space, and Technology] by whistleblowers appears to show that the Karl study was rushed to publication despite the concerns and objections of a number of NOAA scientists." The letter states that “Dr. Karl rushed to publish the study before all appropriate reviews of the underlying science and new methodologies used in the foundational climate datasets were conducted.”

Why would the study be rushed? Rep. Smith writes that “the timing of its release raises concerns that it was expedited to fit the Administration’s aggressive climate agenda.” The June study in the journal Science came out two months before the new EPA “Clean Power Plan” regulations were finalized, and five months before the upcoming international climate negotiations in Paris.

Referring to the scientists' e-mails, which he has subpoenaed, Rep. Smith writes, “If you do not produce the requested material by Friday, November 20, 2015, I will be forced to consider the use of compulsory process.” Rep. Smith is also postponing the closed-door interviews he had requested with several NOAA scientists and staff in the meantime.

An aide for the House Science Committee declined to disclose to Ars whether the whistleblowers were NOAA staff, or any other details about the nature of the information they have provided, citing a desire to protect their identity. The information Rep. Smith refers to has not been shared with House Science Committee Democrats, either.

When asked to comment, NOAA provided Ars with the following statement:

The notion that this paper was rushed to publication is false. In December 2014, the coauthors of the study submitted their findings to Science—a leading scientific journal. Following a rigorous peer-review process, which included two rounds of revisions to ensure the credibility of the data and methodologies used, Science informed the authors that the paper would be published in June. The notion that NOAA is “hiding something” is also false. We have been transparent and cooperative with the House Science Committee to help them better understand the research and underlying methodologies. We have provided data (all of which is publicly available online), supporting scientific research, and multiple in person briefings. We have provided all of the information the Committee, or anyone else, needs to understand, verify, or challenge the paper's findings. We stand behind our scientists who conduct their work in an objective manner. As we've said before, there is no truth to the claim that the study was politically motivated or conducted to advance an agenda.

Ars also reached out to the office of Commerce Secretary Penny Pritzker for comment, but no response was received as of press time.

The NOAA study that was published in Science presented the latest version of the agency's global surface temperature dataset and explored changes to the specific warming trend from 1998 to 2014. The update came from folding in a pair of previously published datasets: a new database of terrestrial weather stations, and the most recent version of a database of sea surface temperatures that included some corrections for non-climatic factors like changes in measurement techniques.

The weather station database was published in Geoscience Data Journal in June 2014, and NOAA processed the raw data using the same methods it had used before; those methods were published in 2011. The sea surface temperature database, which Rep. Smith appears to view with suspicion, was published in the Journal of Climate in February 2015, but started the peer review process in December 2013. (As any researcher can tell you, peer review can drag on for a long time.)

As of press time, an aide for the House Science Committee had not clarified why this series of events was being described as a rush “to publish the study before all the appropriate reviews of the underlying science” were completed. NASA incorporated this same sea surface temperature database into ts own global surface temperature dataset back in July. Ars asked whether Rep. Smith plans to investigate NASA’s decision as well, but a response was not immediately provided.

Meanwhile, the Washington Post published a letter to the editor from Rep. Smith Tuesday, in which he wrote, “In June, NOAA employees altered temperature data to get politically correct results and then widely publicized their conclusions as refuting the nearly two-decade pause in climate change we have experienced. The agency refuses to reveal how those decisions were made.”

Setting aside the fact that global temperatures have increased in all of the major surface temperature datasets over that time period, and the oceans (where the vast majority of heat energy added due to our greenhouse gas emissions has gone) have continued warming apace, all of NOAA’s data and methods are publicly available.

Rep. Smith’s letter to the editor closes with a familiar argument: “If NOAA has nothing to hide, why not provide the communications to support the agency’s claims?”

On Wednesday, the House Science Committee, which Rep. Smith chairs, was holding a hearing in which invited speakers criticized new US greenhouse gas emissions regulations and future pledges as expensive and incapable of having a significant effect on global climate.