While Idaho teachers can still choose to include climate change in their lesson plans — and many do in places like Boise, the state’s capital and biggest city — science educators said they were concerned for teachers in districts where climate change was considered more controversial. Without state standards, those teachers might choose not to teach climate change at all, said Christopher Taylor, the science supervisor for the Boise School District.

Mr. Taylor said he was not worried about his own district. “It’s these small rural districts,” he said. “They will do what the state says.”

Even in Boise, “When you teach environmental science, you’re constantly being discredited,” said Erin Stutzman, a science teacher at Timberline High School in the capital, which, along with other schools nationally, has been mailed anti-science materials from the Heartland Institute, a group that denies the reality of human-induced climate change.

“If the community opposes it or thinks it’s some kind of propaganda, it puts those children coming out of those districts at a major disadvantage,” Ms. Stutzman said. “It’s an equity issue.”

Only 24 percent of Republicans in solid-red Idaho agree with the scientific consensus that climate change is caused mostly by human activities, according to the Yale Program on Climate Change Communication, the lowest percentage of any state.

“It’s a political issue, and it shouldn’t be a political issue,” Mr. Taylor said.

The public response to the new proposal appears to be largely positive. House lawmakers heard testimony last week from 28 people, all of whom spoke in favor of the revised standards. And roughly 1,000 comments were received during the public comment period, only five of which were negative, Mr. Cook said.

Emily Her, 17, a student of Ms. Stutzman’s, testified at the hearing and is leading a petition that supports the teaching of climate change in Idaho. She said she was not afraid to speak up about the standards in Boise, but worried about people her age in districts where climate change may not be part of the curriculum. “It really puts the students at a disadvantage when the teachers have fear,” she said.