Natural gas Environmental effects
Effect of natural gas
Natural gas is mainly composed of methane. After release to the atmosphere it is removed by gradual oxidation to carbon dioxide and water by hydroxyl radicals (OH− ) formed in the troposphere or stratosphere, giving the overall chemical reaction CH 4 + 2O 2 → CO 2 + 2H 2O.While the lifetime of atmospheric methane is relatively short when compared to carbon dioxide, with a half-life of about 7 years, it is more efficient at trapping heat in the atmosphere, so that a given quantity of methane has 84 times the global-warming potential of carbon dioxide over a 20-year period and 28 times over a 100-year period. Natural gas is thus a more potent greenhouse gas than carbon dioxide due to the greater global-warming potential of methane.2009 estimates by the EPA place global emissions of methane at 85 cubic kilometers (3.0 trillion cubic feet) annually,or 3% of global production, 3.0 trillion cubic meters or 105 trillion cubic feet (2009 est).Direct emissions of methane represented 14.3% by volume of all global anthropogenic greenhouse gas emissions in 2004.
During extraction, storage, transportation, and distribution, natural gas is known to leak into the atmosphere, particularly during the extraction process. The amount of methane leaking due to fossil fuel extraction had long been underestimated. The possibility to reduce warming quickly by eliminating methane emissions means that this is an effective and quickly-responding climate change mitigation strategy. This is targeted by efforts such as the Global Methane Inititative. In 2021 MethaneSAT should reduce the large uncertainties in the estimates.
Carbon dioxide emissions
Natural 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 CO 2 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 would be the source of 11 billion tons a year, with coal and oil now 8.4 and 17.2 billion respectively because demand is increasing 1.9% a year. According to Global Energy Monitor, gas pipelines built in the 2010s, especially in the United States, are locking in huge greenhouse gas emissions for 40 to 50 years at a time.
To reduce its greenhouse emissions, the government of the Netherlands is subsidizing a transition away from natural gas for all homes in the country by 2050. In Amsterdam, no new residential gas accounts are allowed as of July 1, 2018, and all homes in the city are expected to be converted by 2040.(to what?)