But seven ambassadors among more than a dozen credentialed diplomats also acknowledged there are continuing disagreements over increasing ship traffic, and noted the lack of infrastructure and the inability to respond to human safety or environmental emergencies in a timely manner.

All said their governments are dedicated to cooperative resolution of disagreements, while internationally recognized researchers warned that quickly changing circumstances could overcome good intentions.

"We are still, as a nation, learning our responsibilities," Mead Treadwell, chairman of the U.S. Arctic Research Commission, said at the opening of the conference, titled Changes in the Arctic Environment and Law of the Sea, held in Seward May 20-23.

The commission cosponsored the 33rd annual conference of the Center for Ocean Law and Policy, a University of Virginia Law School think tank.

More than 100 participants from 12 countries, ranging from China to Monaco, heard panel discussions on maritime boundaries, transportation, marine safety, and impacts to humans and the environmental.

Status reports were given on such issues as the ongoing expansion of icebreaking, military capability of northern countries, and the disputed ownership of Han Island, a small, uninhabited island between Canada and Greenland.

The core players in the Arctic debate are the coastal states of Russia, Canada, Norway, the U.S. and Denmark, through its ownership of Greenland.

The existing 200-mile exclusive economic zones of the five and so-called extended continental shelves (ECS) they can claim under the existing procedures are believed to hold most of the oil, gas and mineral wealth that is becoming increasingly available.

Finland, Sweden and Iceland have a stake in the debate because of their claims east of Greenland, where there is no agreed boundary between the North Atlantic and the Arctic Oceans. Most of the rest of the world is interested because of shipping, fishing and security interests.

The European Commission staked its position with a May 2008 resolution calling on its member nations to support the principle of freedom of navigation in the Arctic Ocean. The coastal states responded with the Ilulissat Declaration, named for the Icelandic city where it was signed last November.

"The nations that signed the Ilulissat Declaration signaled they are not interested in an Arctic treaty, at least not modeled on the Antarctic," said Ambassador David Balton, State Department deputy assistant secretary for oceans and fisheries.

Russia has committed to building at least six new Arctic-capable carrier battle groups by 2030, participants were told. Norway has received delivery of three of five frigates bearing U.S. Aegis missile systems and last November announced the purchase of 48 U.S. F-35 stealth fighter planes. Canada is building as many offshore patrol vessels and spending $720 million on new icebreakers. Both Canada and Russia plan to expand land-based Arctic military units and facilities.

The multiple overlapping Arctic maritime boundary claims are in various stages of resolution by the Commission on the Limits of the Continental Shelf (CLCS), a part-time panel of 21 international experts who administer a formulaic resolution process established under the United Nations Convention on the Law of the Sea (UNCLOS).

ECS claims beyond currently known limits may be based on what a country considers its most beneficial combinations of optional formulas in UNCLOS based on the sea floor's geographic structure, contours and sediment thickness.

The U.S. is believed to have an ECS the size of California off Alaska's coast, but it is ineligible to submit a claim or even to international recognition of its current 200-mile exclusive economic zone because the U.S. Senate has not yet ratified the Law of the Sea.

Under the treaty a country must submit its boundary claims, supported by scientific evidence, to the CLCS, and accept the panel's recommendations, to allow it to claim international recognition of borders. The CLCS is not a mediation agency, but does consider disputed claims such as those between the U.S. and Canada.

Canada sees the maritime boundary as an extension of the land boundary along the 141st Meridian to the North Pole. The land boundary stops at the shore, according to the U.S., which would get 6,700 square miles of Arctic EEZ under the equidistant line it claims is the maritime boundary.

Marine transport issues are equally complex.

The U.S. and the European Union maintain that the Northwest Passage is an international strait open to unrestricted passage by commercial and military surface vessels, as well as to submarines and aircraft.

Canada is not proposing to restrict so-called innocent passage, the internationally recognized right for a vessel to cross a country's waters in the course of peaceful voyages, but has long claimed the route as internal waters where vessels are subject to Canadian laws and boardings.

The Canadian Parliament is currently considering a proposal that would require international vessels of 300 tons and larger to report their presence when they reach the 200-mile limit.

The U.S. Coast Guard is in the midst of a multi-year waterways analysis to determine what aids to navigation are needed on likely Arctic sea routes. Adm. Arthur Brooks, USCG commander in Alaska, acknowledged at the conference that he does not have the capability for a timely response to a marine casualty. Response vessels may have to be dispatched from Kodiak and could take days to arrive at the scene of an emergency if they encountered difficult ice conditions.

Rob Huebert, a University of Calgary political scientist and fellow at its Center for Military and Strategic Studies, raised a more chilling prospect during a panel discussion: "What happens when an Iranian research vessel decides that it wants to apply for permission under the regime of consent to engage in research in the American EEZ?"

A constant of the conference was the pace of change and the lack of baseline scientific knowledge to provide some indication of what, and how much, to expect in the next few years. A May 2009 report to the Canadian Parliament on challenges facing its coast guard said potential shipping lanes could be ice free in summer by 2015. In this context, ice free means no longer solidly covered.

Steven Macko, a University of Virginia geochemist, said during a discussion on environmental issues that methane released into the atmosphere as Arctic peat is exposed and thawed could have 10 times the effect of carbon dioxide on earth temperatures, but that prospect is not being closely studied.

"All of the models that you saw of global warming are linear. They are predicting small amounts of increase in temperature and the effects. None bring into consideration abrupt climate change. If there is catastrophic loss of gas hydrate or methane from the Arctic, we could see catastrophic change in earth's temperatures," Macko said.

Similar potentials for synergies of uncertainty overlaid every issue facing the Arctic governments. Impacts to the lives and cultures of Alaska's Native coastal residents are more complex in Canada and Greenland, where aboriginal peoples actually live much of the year on the icepack among the Queen Elizabeth Islands, said Huebert.

"We've been somewhat remiss in incorporating some elements of aboriginal realities in terms of cooperation," he said.

Earl Kingik, an Inupiat whaler from Point Hope and the only aboriginal Native among nine panelists of speakers, said climatic changes first noticed 15 years ago are increasing.

"Ever since tour ships showed up we're beginning to see trash on our beaches we've never seen before," Kingik said.