Transport in general is subject to widely varying taxes between different countries. One important component of transport, however, is almost universally exempt from taxation, precisely because of its international nature: the 'bunker fuels' used in international aviation and marine transport. However, the Kyoto Protocol instructs Annex I parties specifically to ' ... pursue limitation or reduction of emissions of greenhouse gases not controlled by the Montreal Protocol from aviation and marine bunker fuels, working through the International Civil Aviation Organization (lCAO) and the International Maritime Organization (IMO), respectively ... '.1 The question of the possible application of such taxation is therefore a pertinent one.