Internal combustion engine the atmosphere by the reaction of and volatile organic compounds in the presence of sunlight. Ground-level ozone is harmful to human health and the environment. Though the same chemical substance, ground-level ozone should not be confused with stratospheric ozone, or the ozone layer, which protects the earth from harmful ultraviolet rays. Carbon fuels contain sulfur and impurities that eventually produce sulfur monoxides (SO) and sulfur dioxide (SO) in the exhaust, which promotes acid rain. In the United States, nitrogen oxides, PM, carbon monoxide, sulphur dioxide, and ozone, are regulated as criteria air pollutants under the Clean Air Act to levels
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