The participation of a UK science vessel in a voyage through the Northwest Passage by Crystal Cruises is reported to have triggered concerns.
The RRS Ernest Shackleton is funded by the UK government and normally carries out support work for the British Antarctic Survey.
But the icebreaker has been chartered this summer to accompany Crystal Serenity on its first voyage in the Arctic.
Critics say it is inappropriate for a vessel dedicated to science to support tourism in such a fragile area, the BBC reported.
Global warming has seen a rapid rise in the number of ships travelling through Arctic waters in recent years.
The Northwest Passage – a shortcut from Asia to Europe through the Canadian Arctic – first became fully clear of ice in the summer of 2007
Since then only a handful of ships have travelled the route – 17 in 2015, according to the US Coast Guard.
Crystal Serenity aims to become the biggest passenger ship yet to attempt to sail the route on a 32-day voyage.
Starting in Alaska on August 16, the will travel 1,500km across the top of Canada, ultimately ending in New York. Fares start at £15,557 per person.
While the route is accessible to ships, it is not ice-free and Crystal has has chartered the RRS Ernest Shackleton, from the British Antarctic Survey.
The vessel is normally used as a logistic support and research ship for UK scientific activities in the Antarctic.
Professor Michael Byers from the University of British Columbia told BBC News: “There is a significant tension between the science and environmental mission of the Shackleton and its participation in an exercise in tourism that has an enormous per capita carbon footprint.”
Prof Byers, who holds a chair in global politics and international law, was invited on the trip to give a series of lectures to passengers. He refused, as he believes this summer’s trip will only encourage others.
“This voyage is a significant contribution, at least on a per capita basis, to climate change by people who are going to see an ecosystem before it is destroyed by climate change. I find that irony quite terrible,” he said.
The British Antarctic Survey said it had chartered the Shackleton to Crystal Cruises as the ship would not be deployed in the Antarctic at that time.
“Cruise ship tourism in both polar regions is well-regulated,” it said.
The chartered icebreaker is to “provide operational support to Crystal Serenity as well as the facility to carry additional expert guides and crew. Specialised safety equipment will be onboard. Zodiacs and helicopters are operated by Crystal”.