The Bureau of Ocean Energy Management (BOEM) recently released a revised environmental analysis of oil and gas activity in the Arctic Ocean.

BOEM’s latest analysis leaves no doubt that development and production of the Chukchi Sea oil and gas leases could be devastating to the Arctic marine ecosystem. Perhaps most troubling, a statistical analysis used by BOEM indicates that there is a 75% chance of one or more large spills over the lifetime of Chukchi Sea development and production. BOEM admits that a very large oil spill could result in the death of large numbers of polar bears, bowhead whales, seals, and marine and coastal birds.

The agency is accepting comments until December 22. Join Ocean Conservancy in telling BOEM to say no to risky Arctic drilling.

This environmental analysis and opportunity to comment has been a long time in the making. Almost seven years ago, in February of 2008, the federal government auctioned oil and gas leases in the Chukchi Sea off the northwest coast of Alaska. The auction was known as Lease Sale 193, and it purported to give successful lessees—including Shell—the conditional right to drill for oil in the Arctic Ocean.

But there was a major problem. In 2010, a federal court found that the environmental analysis underpinning Lease Sale 193 was unlawful; the court required the government to revise its analysis and reconsider the sale. Unfortunately, the government failed to fix all the problems and in January of 2014, another federal court ruled that the revised environmental analysis was faulty. In response, the government announced that it would prepare yet another revision and once again reconsider the sale of the leases.

All of which brings us to the end of October, when BOEM released its third major environmental analysis of the 2008 lease sale: the Draft Second Supplemental Environmental Impact Statement Lease Sale 193.

Beyond the 75% chance of one or more large spills, as we’ve described before, there is no way to effectively clean up a large oil spill in Arctic waters. Constantly changing sea ice, fog, high winds, extreme cold, remoteness and lack of shoreline infrastructure all combine to make meaningful cleanup all but impossible. And after Shell’s error-riddled 2012 drilling season, it is clear that we cannot trust oil companies to operate safely and responsibly in the Arctic.

Drilling for oil in the Arctic Ocean is risky business. BOEM’s latest environmental analysis demonstrates that the consequences of a mistake are enormous. Join with Ocean Conservancy in telling BOEM to protect the Arctic Ocean by saying no to drilling in the Chukchi Sea.