section_path: Environmental effects/Greenhouse gas emissions
section_name: Greenhouse gas emissions
paragraph_text: Greenhouse gas emissions
  
  When refined and burned, natural gas can produce 25–30% less carbon dioxide per joule delivered than oil, and 40–45% less than coal. It can also produce potentially fewer toxic pollutants than other hydrocarbon fuels. However, compared to other major fossil fuels, natural gas causes more emissions in relative terms during the production and transportation of the fuel, meaning that the life cycle greenhouse gas emissions are about 50% higher than the direct emissions from the site of consumption.
  
  In terms of the warming effect over 100 years, natural gas production and use comprises about one fifth of human greenhouse gas emissions, and this contribution is growing rapidly. Globally, natural gas use emitted about 7.8 billion tons of CO in 2020 (including flaring), while coal and oil use emitted 14.4 and 12 billion tons, respectively. The IEA estimates the energy sector (oil, natural gas, coal and bioenergy) to be responsible for about 40% of human methane emissions. According to the IPCC Sixth Assessment Report, natural gas consumption grew by 15% between 2015 and 2019, compared to a 5% increase in oil and oil product consumption.
  
  The continued financing and construction of new gas pipelines indicates that huge emissions of fossil greenhouse gases could be locked-in for 40 to 50 years into the future. In the U.S. state of Texas alone, five new long-distance gas pipelines have been under construction, with the first entering service in 2019, and the others scheduled to come online during 2020–2022.