Espen
Interesting number. Out of curiosity I was wondering how many ships that might mean.
In 2011 China's container port traffic was 140 million teu's (an industry measure - a teu is the equivalent to a 20ft sea container).
From Wiki the average size of a container ship is roughly 10,000 teu's (there are a few as large as 16,000).
14,000 container ship loads then in 2011 for China.
15% would then work out to 2100 ships crossing the arctic just from China!! Yikes!!
Considering all the other countries who would also be using the Arctic Ocean routes we could be looking at several thousand crossings a season.
For reference I found reports that the number of crossings of the Northern Sea Route in 2012 was about 60 and the number of trips through the Northwest passage was 20 or so. Even if we assume that the Arctic total was 100 passages last year then we are talking about an increase of around 30 times in 7 years. I can only imagine the impacts.