International Maritime Organization (IMO) oversees Shipping & Maritime affairs for the United Nations and has been pivotal in introducing legislation pertaining to marine fuel. Part of the IMO, MEPC has become the lead source of information on MARPOL Annex VI.
DG Environment has been tasked, as part of the European Commission, with implementing measures to improve air quality in the European Union. In addition, DG Environment on Shipping is the main European source for shipping & environmental documents.
In terms of the legislative process in Europe, the European Parliament has delegated most work to their Environment Committee, while the Council of the European Union is where Ministers of the EU Member States debate legislation.
At a state level, the California Air Resources Board has implemented regulations for ships operating in California ports and associated waters.