Environmental impact of the energy industry to virtually all aspects of present society, especially for transportation and heating for both homes and for commercial activities. Natural gas is often described as the cleanest fossil fuel, producing less carbon dioxide per joule delivered than either coal or oil., and far fewer pollutants than other fossil fuels. However, in absolute terms it does contribute substantially to global carbon emissions, and this contribution is projected to grow. According to the IPCC Fourth Assessment Report, in 2004 natural gas produced about 5,300 Mt/yr of CO emissions, while coal and oil produced 10,600 and 10,200 respectively (Figure 4.4); but by 2030,
Ocean storage of carbon dioxide IEA Greenhouse Gas R&D Programme estimates that dilute carbon dioxide injection would cost $70 per tonne of carbon dioxide including costs of carbon capture, transport, and storage before boat dispersal. Carbon dioxide ocean storage can occur through solid or solid hydrate of carbon dioxide. The solid state density of carbon dioxide is approximately 1.5 times greater than seawater and thus tends to sink to the ocean floor. The dissolving rate at the surface is about 0.2 cm/hr such that a small quantity of carbon dioxide can be completely dissolved before reaching the sea floor. In addition to solid carbon dioxide