Climate change will pose major new hurdles for U.S. naval forces, forcing the military to grapple with an emerging Arctic frontier, increasing demand for humanitarian aid and creating rising seas that could threaten low-lying bases, the National Academy of Sciences said yesterday.

"Even the most moderate current trends in climate, if continued, will present new national security challenges for the the U.S. Navy, Marine Corps and Coast Guard," concludes a new academy report. "While the timing, degree and consequence of future climate change impacts remain uncertain, many changes are already underway in regions around the world ... and call for action by U.S. naval leadership in response."

The analysis, conducted at the Navy's request, echoes similar reports authored by the Defense Department, the intelligence community and the Navy's own Task Force Climate Change.

Much of its focus is on the far north, where rising temperatures are decreasing the portion of the oil- and gas- rich Arctic Ocean that is covered by sea ice. By 2030, ice-free periods during late summer could be long enough to create new sea lanes through the polar region, the new report says.

Handling the expected crush of shipping and tourist traffic, along with increased oil and gas exploration and military activity by other nations, will require U.S. naval forces to transform their fleets, from officer training to the mix of ships they employ.

That will be especially challenging because the United States' capacity to operate in the harsh polar environment has degraded since the end of the Cold War, the NAS report says.

A case in point: the United States' aging fleet of of just three icebreakers capable of operating in the Arctic.

Few ice-capable ships and no training
One ship, the Polar Star, sits in a Seattle dock in "caretaker" status, undergoing repairs. The Coast Guard hopes to have the vessel back at sea by the end of 2013.

The service plans to decommission another ship that is now operating, the Polar Sea, because needed engine repairs would be cost-prohibitive. Decommissioning the Polar Sea will also free up money needed to finish the Polar Star's repairs.

"As old as they are, and with what it costs to maintain and keep them up, we had to make some difficult choices," said a Coast Guard spokesman, Lt. Paul Rhynard. "With the funding we were given to fix them both, we could only effectively fix one."

The service expects to take the Polar Star out of service at some point before the Polar Sea is seaworthy, leaving only one icebreaker, the Healy, in use. That ship was designed as a scientific research vessel and is less useful for military missions.

The new report also calls for new programs to train Marine Corps units to survive and sustain themselves in the Arctic.

"To my knowledge, we have almost backed out of this cold-weather training," said Frank Bowman, a retired Navy admiral and co-chairman of the committee that wrote the science academy report.

Opening up the Arctic isn't necessarily a recipe for increased conflict, the report says, but the prospect of tapping the region's oil and gas deposits, fisheries and potential new shipping lanes has created a "complex and nuanced" geopolitical situation.

Several Arctic countries are entangled in long-running disputes over their maritime boundaries, including Canada and the United States, Canada and Denmark, and Norway and Russia.

A treaty that might help remains unratified
The "most notable" disputes are those involving claims to extend countries' outer continental shelves under the U.N. Law of the Sea Convention, the NAS report says.

The United States is the only major industrialized nation that has not ratified the treaty, which took effect in 1994, despite a broad base of supporters that include the military, mining interests, the oil and gas industry and environmental groups.

Doing so would give the Navy, Marines and Coast Guard "maximum operating flexibility in the Arctic," the science academy says.

"The [treaty] is really important, because that impacts our credibility when we talk to other Arctic nations," said Capt. Tim Gallaudet, deputy director of the Navy's Task Force Climate Change. "They say, 'You say that now, but how can we trust you?'"

But while changing conditions in the Arctic present the most immediate, obvious implications for the U.S. fleet, according to Busalacchi, the new report also outlines emerging issues in other parts of the globe. They include an increased demand for Navy and Marine Corps aid during humanitarian crises, like last year's earthquake in Haiti.

Such missions are likely to emerge as the greatest change to U.S. naval forces' current operations, the science academy says, warning that climate change is likely to cause more frequent or severe droughts, floods, storms and other disasters that could strain military resources and national security missions.

The Navy currently has two hospital ships available, the Comfort and the Mercy. If those ships are retired when the service's budget is tight or if more resources are needed for a large disaster, naval forces should consider leasing out such ships from private companies, the report suggests.

"It's not just a matter of having a large space [for these operations] -- you need a surgical setup, you need a trauma setup, you need beds and you need the proper equipment," Bowman said.

Gallaudet said that leasing ships would make sense, because they are not needed on a consistent basis. He also noted that naval forces could also draw on their aircraft carriers and amphibious ships with large medical facilities to render humanitarian aid.

Rising seas could flood bases
Another pressing climate change impact confronting the Navy, Marine Corps and Coast Guard is the effect rising seas will have on their low-lying bases and other facilities.

The NAS report says the Navy should expect anywhere from 1.3 to 6.5 feet of sea level rise through the end of the century, with the most likely rise being 2.6 feet.

But those are values for the global average sea level rise, the report notes, cautioning that erosion and subsidence of coastal areas could exacerbate the impact of rising waters in many areas. And even without inundation, a gradual rise in sea level is also likely to increase naval installations' vulnerability to storm surge and increase the height of waves.

Taken together, the laundry list of potential climate impacts on naval operations is daunting, said Jay Gulledge, senior scientist at the Pew Center on Global Climate Change.

"Even though I've been looking at these issues for a few years, this actually drove home to me that the potential for climate change to stress the capability of the naval forces is actually pretty large," he said. "If you think about it, you've got several things going on at the same time, all of which could overtax the Navy's capability."

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC., 202-628-6500