Shipping is a global industry operating around 100,000 ships of varying specialist types. Ships use bunker fuel, the tail end of the oil refining process that emits a cocktail of gases that harm both the planet and human health. The low grade is more like asphalt than oil and has to be super-heated to liquefy it. Along with CO2, there are nitrogen oxides and sulphur oxides (the cause of acid rain) as well as what is known as particulate matter: sooty particles that are responsible for an estimated 60,000 human deaths among populations in port and coastal conurbations where they accelerate heart and respiratory conditions.

The global shipping trade, despite being the most cost effective and environmentally efficient mode of transport, is responsible for emitting a billion tons of CO2 a year and as the global economy recovers, this figure is bound to escalate. This means shipping, as a single industry, is a larger CO2 emitter than an entire industrialised country like Germany and if it were a country, it would rank no 6 in the world CO2 league table.

Because of the global nature of shipping, where a single voyage will cross many different territorial waters, the responsibility for shipping emissions was passed to the IMO (International Maritime Organisation) at Kyoto. The IMO is the maritime division of the United Nations.

In over a decade since Kyoto, the IMO has been unable to get unanimity of agreement on ways to reduce CO2 emissions. The failure of the Copenhagen Summit to set targets further reduces hopes that the IMO will reach a mandatory proposal for CO2 emission reduction from international shipping.