What Is the Scale of the Global Economy?

Today 90% of world cargo moves by ship, including 60 % of world trade in oil. Oil itself is about 30 per cent of all the cargo that is carried aboard ships. There seems to be very little engineering or regulatory limits to how big the ships can get and how often they can travel. It seems to me that we're living in this slightly distopian era in which everything seems to be possible. And i call that distopiun because everything seeming to be possible also has other after effects, especially when it comes to ecology.