AUSTIN, Texas (AP) — How science textbooks in Texas address climate change is at the center of a key vote expected Friday after some Republican education officials criticized books for being too negative toward fossil fuels in America’s biggest oil and gas state.

The issue of which textbooks to approve has led to new divisions on the Texas State Board of Education, which over the years has faced other heated curriculum battles surrounding how evolution and U.S. history is taught to the more than 5 million students.

Science standards adopted by the board’s conservative majority in 2021 do not mention creationism as an alternative to evolution. Those standards also describe human factors as contributors to climate change.

But some Republicans on the 15-member board this week waved off current textbook options as too negative toward fossil fuels and for failing to include alternatives to evolution. One of Texas’ regulators of the oil and gas industry, Republican Wayne Christian, has urged the board to “choose books that promote the importance of fossil fuels for energy promotion.”

Texas has more than 1,000 school districts and none are obligated to use textbooks approved by the board. Still, the endorsements carry weight.

“Members of the board are clearly motivated to take some of these textbooks off of the approved list because of their personal and ideological beliefs regarding evolution and climate change,” said Glenn Branch, deputy director of the National Center on Science Education.

Friday’s vote will decide whether the proposed textbooks meet the standards set in 2021. Branch said multiple books comply with the regulations set then by the board and follow the consensus of the scientific community.

Scientists overwhelmingly agree that heat-trapping gases released from the combustion of fossil fuels are pushing up global temperatures, upending weather patterns and endangering animal species.

Aaron Kinsey, a Republican board member and executive of an oil field services company in West Texas, criticized photos in some textbooks as negatively portraying the oil and gas industry during a discussion of the materials this week.

“The selection of certain images can make things appear worse than they are, and I believe there was bias,” Kinsey said, according to Hearst Newspapers.

“You want to see children smiling in oil fields?” said Democrat Aicha Davis, another board member. “I don’t know what you want.”

In a letter Thursday, the National Science Teaching Association, which is made up of 35,000 science educators across the U.S., urged the board not to “allow misguided objections to evolution and climate change impede the adoption of science textbooks in Texas.”

How many textbooks the board could reject depends on the grade level and publisher, said Emily Witt, a spokeswoman for the Texas Freedom Network, a left-leaning watchdog of the board. She said their organization had identified only two textbooks that would not meet the standards set in 2021.