Republican presidential candidate Sen. Ted Cruz of Texas is holding a hearing in the Commerce Committee Tuesday meant to address the "ongoing debate" on climate science, according to the committee.

Democrats are already coming out in force to challenge the hearing, which they say will be used to dismiss climate change as a scientifically supported phenomenon and a core challenge for all governments worldwide.

Cruz is the chairman of the Space, Science, and Competitiveness subcommittee, which will convene the hearing, called "Data or Dogma? Promoting Open Inquiry in the Debate over the Magnitude of Human Impact on Earth's Climate."

"The hearing will focus on the ongoing debate over climate science, the impact of federal funding on the objectivity of climate research, and the ways in which political pressure can suppress opposing viewpoints in the field of climate science," the committee said.

The hearing comes a few days before a major United Nations climate change conference is expected to wrap up on Friday in Paris. President Obama has made reaching a deal on greenhouse gas emissions at the conference one of the key focuses of his last remaining year in office. Many scientists blame greenhouse gas emissions for causing the Earth's climate to warm from the burning of fossil fuels, such as coal and oil.

Cruz has been an outspoken critic of the Environmental Protection Agency's regulations to reduce greenhouse emissions from power plants, which are the centerpiece of the president's climate change agenda and key to meeting U.S. commitments to any deal that emerges this week.

"Climate change is not science. It's religion," he told Blaze TV in October. "Look at the language, where they call you a denier. Denier is not the language of science … Any good scientist is a skeptic; if he's not, he or she should not be a scientist. But yet the language of the global warming alarmists, 'denier' is the language of religion, it's heretic, you are a blasphemer."

Cruz ranks second currently in the Washington Examiner's presidential power rankings.

Sen. Gary Peters of Michigan, the top Democrat on the subcommittee, will join his fellow Democrats ahead of the hearing in a press conference "to urge Republicans to stop denying that climate change is real and work with Senate Democrats to address its devastating impacts."

Democrats said Cruz's hearing will host "controversial witnesses aimed at denying the existence of climate change, comes on the heels of historic meetings in Paris where more than 190 world leaders are gathering to negotiate an international plan to address climate change."