Late in 2011, Sen. Lisa Murkowski of Alaska slipped a policy rider into the fiscal 2012 omnibus spending package, transferring from the EPA to the Interior Department the air quality permitting process for drilling oil in the Beaufort and Chukchi seas off Alaska’s northern shore.

It was a seemingly benign move. The Alaska Republican noted that the Interior Department already was responsible for air permitting at most Gulf of Mexico drilling operations. She said it only made sense to have a consistent set of rules enforced by a single agency.

The idea was to streamline the permitting process by consolidating authority in a department with a reputation for moving more expeditiously.

Today, rising Arctic temperatures and melting sea ice, which climatologists view as signs of impending peril, spell opportunity for energy companies eager to tap newly accessible offshore oil and gas reserves. Some companies have gotten a green light to drill in Alaska’s abundant offshore oil deposits, and others hope to follow soon.

Environmentalists worry, however, that the Interior Department’s Bureau of Ocean Energy Management lacks the capability or resources to consider fully the effects of air pollution in the Arctic environment. They say the agency’s regulatory structure, more than 30 years old, was tailored for conditions in the Gulf of Mexico.

To them, a little-noticed shift in jurisdiction for enforcing clean-air laws at drilling operations could jeopardize air quality in the pristine region.

“EPA has a long history of protecting air and water — including making sure that places like the Arctic with very clean air stay that way,” said Michael LeVine, a senior counsel at the environmental group Oceana. He said the Interior agency “has not been responsible for implementing comprehensive protections, like those in the Clean Air Act, in the Arctic, and there is reason to be concerned about the resources and expertise available in the agency.”

After years of delays and setbacks, Shell Oil Co. began exploratory drilling in the Chukchi Sea in September, before shutting down for the season. The Interior Department estimates that the Chukchi Sea may hold as much as 15 billion barrels of crude petroleum and the Beaufort Sea up to 8 billion barrels, reserves that the oil industry is eager to develop.

Concerns about the risks of drilling, however, were amplified by the 2010 Deepwater Horizon spill in the Gulf of Mexico. Critics warned that hostile weather conditions and a lack of infrastructure for a quick response could make a similar spill in the Arctic far more catastrophic.

But even without an accident, there are day-to-day environmental effects of oil and gas exploration and production, including air pollution from drilling ships, support vessels and ice breakers as well as the generators that provide power to the rigs.

The 1980 air quality rules for offshore drilling in the Gulf of Mexico include a distance-based formula that exempts some operations far offshore — depending on how much and what type of pollution they emit — from installing required pollution control technologies.

Critics say that wouldn’t work in the Arctic, where subsistence native hunters and fishermen in the Arctic roam far offshore and would be affected by pollution even from rigs out at sea. In addition, they worry that even emissions distant from the shoreline could have serious consequences for the fragile environment.

The regulations developed for the gulf assume pollution is emitted gradually over 12 months. Critics say those standards would be ineffective in the Arctic, where drilling would be concentrated in a three-to-four month season. Aides to Murkowski, however, say the rules should be sufficiently stringent for an area with little industry and fewer drilling rigs than the gulf.

“That’s not a reason for arguing for laxer standards” in the Arctic, an aide said. But he added the rules in the Arctic also should not be stricter.

Colin O’Brien, an Alaska-based attorney for Earthjustice, said the shift in jurisdiction is not supposed to weaken environmental protection.

“This legislation, as it was advertised in the House and Senate, was billed as a procedural change and not something that was going to undermine air quality or environmental protection,” he said.

The Interior Department says its BOEM is coordinating with the EPA as it begins to implement its Arctic air quality program. The bureau also says it is conducting a “full review” of its entire offshore air quality program in light of the expansion of its jurisdiction to cover Alaska.

Interior Secretary Ken Salazar, in a July letter to the ranking Democrat on the House Energy and Commerce Committee, Henry A. Waxman of California, said the agency is in the process of modernizing the air quality program to take into account the latest science and inherent differences between the Gulf of Mexico and the Arctic. Salazar also pledged to make sure the program is staffed with Arctic air quality experts — a major concern for environmentalists.

But environmentalists worry that any changes to the regulations that result from the review won’t apply to drilling projects with pending applications.

While the change in jurisdiction may have been intended to sidestep a time-consuming and appeals-driven EPA process, environmental groups hope the Interior Department will borrow more than it rejects from the environmental regulator. For instance, they have encouraged the agency to consider implementing an EPA program designed to protect air quality in pristine regions, LeVine said.

“There is a substantial need to make sure that whatever activities we allow in the region are held to the highest standards, and we’re making decisions based on whether those activities can occur while maintaining healthy ocean ecosystems, clean air and clean water,” LeVine said.