Commercial shipping is starting to take the trans-Arctic route seriously after five summers in a row of passable shipping channels. This summer Arctic cargo shipping will be twice what it was last year, according to some estimates. That is still small compared to the Panama Canal traffic, but as shipping companies gain more experience crossing the Arctic, it seems safe to say they will come to rely on the cost savings of the shorter trip between western Europe and east Asia, made possible by melting ice furing the second half of summer.