I read this novel a few years ago and I don't know why I just thought about it now, maybe because we watched a movie set in the Arctic a few evenings ago, but none of that is really important.
The Ice by Laline Paull
It's an 'eco-thriller' set in the near future where the polar ice has melted earlier than anyone had predicted and a shipping route has opened up across the arctic with countries fighting over who controls it. Tourists on cruise ships are up there too to try and see the last polar bears. Oh, plus there is a bit of murder and intrigue.
It's a great novel, hard to put down. Her first book The Bees is really excellent as well.