Democrats and a group of scientists are lashing out at Texas Rep. Lamar Smith over subpoenas sent to the National Oceanic and Atmospheric Administration they believe are meant to intimidate climate scientists.

Smith, chairman of the House Committee on Science, Space and Technology, sent the subpoena on Oct. 13 asking for documents and communications relating to a study published in June by NOAA showing there has been no slowdown in the rate of global warming, as was previously thought. The burning of fossil fuels is believed by many scientists to be causing global warming through the release of greenhouse gases.