Environmental impact of shipping engines can be higher on a port-specific basis. Ultra-low sulfur diesel (ULSD) is a standard for defining diesel fuel with substantially lowered sulfur contents. As of 2006, almost all of the petroleum-based diesel fuel available in Europe and North America is of a ULSD type. In 2016 the IMO has made new sulfur regulations which must be implemented by larger ships by 2020. Of total global air emissions, shipping accounts for 18 to 30 percent of the nitrogen oxide and 9 percent of the sulphur oxides. Sulfur in the air creates acid rain which damages crops and buildings. When inhaled,
Energy conservation in the United Kingdom and LPG make up a small percentage. Carbon emissions from transport have almost doubled over this period. Increasing car usage, increasing engine sizes, and levels of congestion are some of the problem areas, as is increasing air travel. Efforts to reduce emissions of nitrogen oxides, sulphur dioxide and particulates from diesel vehicles have actually led to an increase in fuel consumption and carbon dioxide emissions. Current technology should allow further reductions in emissions without increases in fuel consumption, and hopefully future technology will allow fuel consumption, and therefore CO emissions, to reduce. The basis of Vehicle Excise Duty (VED), also