Pollution from ships has been a big concern for years. This is why by 2020 the sulfur content of marine fuel will be lowered to 0.5%, right now it is at 3.5%. Shipping companies have already started to prepare for the change in regulations. One way to adapt is converting the vessels already in use with LNG engines. Another way is investing in sustainable energy like solar and wind cells aboard. It is possible that very soon there will be more zero emissions ships in use.