Weathering release occurs of Ca and other ions into surface waters. Rainfall is acidic because atmospheric carbon dioxide dissolves in the rainwater producing weak carbonic acid. In unpolluted environments, the rainfall pH is around 5.6. Acid rain occurs when gases such as sulfur dioxide and nitrogen oxides are present in the atmosphere. These oxides react in the rain water to produce stronger acids and can lower the pH to 4.5 or even 3.0. Sulfur dioxide, SO, comes from volcanic eruptions or from fossil fuels, can become sulfuric acid within rainwater, which can cause solution weathering to the rocks on which it
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