BILLINGS — More than half of Montanans consider global warming a serious problem, according to a new poll released Friday, while fewer than a quarter dismiss the issue.

In a statewide survey sponsored by Montana State University-Billings, 56 percent said global warming was a very serious or serious problem. That compares with 23 percent who said it was not even moderately serious.

‘‘It says this issue has entered the mainstream and has got people’s attention,’’ said MSU-B political scientist Craig Wilson, a co-director of the survey.

The telephone poll of 412 adults was conducted Nov. 8-11 and had a margin of error of 5 percentage points.

Scientists say the effects of global warming already are being felt in Montana: shorter winters, earlier spring snow melts and longer, hotter summers that leave streams dry and spur more frequent wildfires.

Asked about the survey’s findings, Gov. Brian Schweitzer said he was a little surprised so many Montanans viewed global warming as a significant problem. Schweitzer has talked often about global warming as part of his energy platform. But he said Friday he had thought he was more interested in the issue than most.

‘‘It turns out I was just with everyone else on this,’’ Schweitzer said.

On other environmental issues, 64 percent said the federal government should allow states to ‘‘terminate’’ endangered gray wolves. Twenty-six percent were opposed to the idea and 10 percent were undecided.

Montana and Idaho have federally approved wolf-management plans that give them the authority to kill wolves following conflicts with wildlife. In Wyoming, which has yet to come up with a management plan acceptable to the U.S. Fish and Wildlife Service, federal wildlife agents handle livestock conflicts.

A federal proposal now under review would give all three states the opportunity to kill wolves if they cause significant declines in herds of big game such as elk.

A survey question about Yellowstone National Park revealed a wide divide among Montanans on how many snowmobiles should be allowed in the park.

Just 37 percent agreed with a park proposal to cap snowmobiles in Yellowstone at 540 machines daily. Thirty-one percent said that would be too many snowmobiles and 16 percent said it was too few.

There was more consensus on the amount of federal wilderness land in Montana. Half of those surveyed said the state’s 3.4 million acres of wilderness is the right amount. Wilderness areas represent about 4 percent of the state’s total land base.

Sixteen percent said that was too much and 22 percent said it was too little. The remainder were undecided.