Natural gas vehicle gas has the highest energy/carbon ratio of any fossil fuel, and thus produces less carbon dioxide per unit of energy. The major difficulty in the use of natural gas is transportation. Natural gas pipelines are economical and common on land and across medium-length stretches of water (like Langeled, Interconnector and Trans-Mediterranean Pipeline), but are impractical across large oceans. Liquefied natural gas (LNG) tanker ships, railway tankers, and tank trucks are also used. CNG is typically stored in steel or composite containers at high pressure (3000 to 4000 psi, or 205 to 275 bar). These containers are not typically temperature controlled,
Coal in Australia of production was exported (389 Mt out of 503 Mt total). Coal mining in Australia has been criticized by members of the environmental movement, due to carbon dioxide emissions during combustion. This criticism is primarily directed at thermal coal, for its connection to coal-fired power stations as a major source of carbon dioxide emissions, and the link to climate change and the effects of global warming on Australia. The burning of coal for electricity produces 29% of Australia's total greenhouse gas emissions, based on 2013-2014 Clean Energy Regulator data. The Carbon Pollution Reduction Scheme, which followed the draft report in