This is one of the most interesting visualizations I have seen in a while. The folks at Kiln created a map of merchant ships around the world, including a breakdown of the contents of the ships, as well as CO2 emissions as a proxy for environmental impact. You can see a fully functioning version of the map below:
Of course shipping routes are critical for Supply Chain, which is what I've been doing lately. It's amazing to see the incredible number of containers that are traveling around the world every day!