Rep. Lamar Smith (R-Tex.), chairman of the House Committee on Science, Space and Technology and a prominent congressional skeptic on climate change, issued the subpoenas two weeks ago demanding e-mails and records from U.S. scientists who participated in the study, which undercut a popular argument used by critics who reject the scientific consensus that man-made pollution is behind the planet's recent warming.

Smith's document request to the National Oceanic and Atmospheric Administration ordered the agency to turn over scientific data as well as internal "communications between or among employees" involved in the study, according to a letter Friday by the House committee's ranking Democrat, Rep. Eddie Bernice Johnson (Tex.).  Johnson accused Smith of "furthering a fishing expedition" by looking for ways to discredit NOAA's study, which was published in June in the peer-reviewed journal Science.

"It is a disturbing trend for the legitimacy of this committee," Johnson said in the letter to Smith. She linked the subpoena to previous requests by the committee's Republican staff seeking information about NOAA's climate researchers, which Johnson called "a serious misuse of Congressional oversight powers." Noting that NOAA routinely publishes supporting data for its studies, Johnson said Smith had "not articulated a legitimate need for anything beyond what NOAA has already provided."

Smith, responding to Johnson's letter, said the subpoena was not "harassment" but "appropriate constitutional oversight."

"This scandal-ridden administration's lack of openness is the real problem," Smith said in a statement released by his office. "Congress cannot do its job when agencies openly defy Congress and refuse to turn over information. When an agency decides to alter the way it has analyzed historical temperature data for the past few decades, it's crucial to understand on what basis those decisions were made."

Smith, a lawyer who became chairman of the science committee in 2013, has repeatedly rejected mainstream scientific views about climate change, while accusing the Obama administration of undermining the U.S. economy with policies that seek to reduce greenhouse gas emissions. In writings and speeches, Smith has frequently cited scientific studies that suggested a slowing or even a halt in the rise of global temperatures since 2000.