Natural gas gas is often described as the cleanest fossil fuel. It produces 25–30% and 40–45% less carbon dioxide per joule delivered than oil and coal respectively, and potentially fewer pollutants than other hydrocarbon fuels. However, in absolute terms, it comprises a substantial percentage of human carbon emissions, and this contribution is projected to grow. According to the IPCC Fourth Assessment Report, in 2004, natural gas produced about 5.3 billion tons a year of emissions, while coal and oil produced 10.6 and 10.2 billion tons respectively. According to an updated version of the Special Report on Emissions Scenario by 2030, natural gas
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