Conditions in the Arctic would make it hard to clean up an oil spill, a U.S. environmental group says. The photo shows a Canadian Coast Guard icebreaker working off Nunavut in the middle of the summer. (Jonathan Hayward/Canadian Press)

An oil spill in the Arctic Ocean would be so hard to clean up that offshore development there should be put on hold, a U.S. environmental group said Friday.

Because of the difficulties, "all proposed oil and gas leasing, exploration and development in the U.S. Arctic should be delayed” until energy companies can ensure they can respond to spills, said Marilyn Heiman, the director of the Pew Charitable Trust's U.S. Arctic program.

A Pew study found that response plans:

• Fail to realistically account for the harsh climate and remote location.
• Make overly optimistic assumptions about a cleanup.

The plans assume that 90 per cent of the oil would be removed after an Arctic Ocean oil spill, even though less than 20 per cent was recovered after a rig operated by petroleum giant BP exploded and sank in the Gulf of Mexico in April.

The Gulf spill took place close to shore in a densely populated area with a gentle climate. Any spill in the Arctic Ocean would face moving ice, punishing sub-zero temperatures and brutal storms with hurricane-force winds. It would be hard to access the spill by land or sea because of the scarcity of roads and the huge distances from ports and U.S. coast guard ships and airfields, the report says.

While the study looks at offshore drilling in Alaska, the situation in Canada is similar.

The Gulf spill would have been even worse in the Arctic, said Trevor Taylor of Oceans North Canada, a Pew-led conservation campaign.

Comparing the response of BP in the Gulf and the capacity that's available in the Arctic, "it is extremely scary," he said.

The report says it would be hard to deploy boats and skimmers to remove the oil, and containment booms could be torn in the tough Arctic weather.

"Low visibility and hurricane-strength wind can make finding and igniting oil slicks impossible," and applying dispersant from aircraft requires low winds and high visibility, which can't be counted on in the Arctic, the Pew report says.

Other recommendations include:

• Planning for a worst-case blowout.
• Figuring out how oil would disperse in the Arctic currents.
• Improving Arctic oil spill science, monitoring and assessment.

The Pew organization is hoping that both Canada and the U.S. develop laws to protect Arctic coastal waters.

A bill before the U.S. Senate would strengthen the review and oversight of all U.S. coastal waters, including the Arctic, while Canada's National Energy Board is running a public review of Arctic offshore drilling regulations. It began the review in May after the Gulf spill. There is no offshore drilling in Canada's Arctic and the board has not received any applications for drilling, it said in September.