[aavci]

What are the environmental impacts of this route becoming more and more active?

More open water means ships can move through places that used to be protected by ice. This would have impact on marine life, fisheries, coastal life.

[gmuslera]

It will have far more impact in the climate of all the world. Ice reflects sunlight, deep water absorbs it, the rate of the planet heating up rises, positive feedback loops should be scary for a reason. At least for something that is not just a new narrow path but a significant portion of ice cover missing on that general area.