There are plenty of Trans-Atlantic freighters that carry passengers; perhaps it's the most popular crossing for freighter travel. Some are listed at freightercruises.com or freighter-travel.com. I've also found some north-west passage freighters, but they connect only Greenland and North-America. Are there any passenger-carrying freighters that connect northern Norway with North-America (preferably a place in North America with onward public transportation) through the Arctic or the high north in general, rather than going south to France/UK/Ireland before crossing the Atlantic?
I found an interesting site that lists a lot of companies and sites that allows you to become a passenger on a freighter. The thing is that there are no direct routes from Norway that I can find to anywhere in North America.
The best I was I able find was routes operated Hamburg Sud from Rotterdam to multiple ports in Norway and from Rotterdam to multiple places in the US. There is also a different German Company Rickmers-Linie which operates through Hamburg and will let you again change ships to Scandinavia (Sweden and Finland) and that's about it.