The exploitation and transport of fossil fuels, including oil, coal and natural gas, have contributed to the release of methane in the world’s subsoil.
The area burned by fires each year decreased about 12% between the early 2000s and the period of 2007 to 2014, and the methane emissions increase would have been even greater otherwise.
19 January 2018: The oil and gas industry is primarily responsible for the increase in methane emissions, according to a study led by the US National Aeronautics and Space Administration (NASA), which explains that methane emission sources have historically been underestimated. The increase equals around 25 teragrams (25 trillion grams) per year since 2006, a finding that underscores the need to transition to renewable energy sources in order to achieve the goals of the Paris Agreement on climate change.
According to the authors, the exploitation and transport of fossil fuels, including oil, coal and natural gas, have contributed to the increased release of methane in the world’s subsoil. The study applies new ground-based satellite data analysis to more accurately identify methane exchanges and a new calculation of emissions from global fires, which have dropped significantly.
The study explains that methane emissions have been increasing significantly since 2006, and research teams produced estimates for two known sources: emissions from the oil and gas industry; and microbial production in wet tropical environments like marshes and rice paddies. However, the sum of the estimated emissions from these and other sources is greater than the observed increase. The researchers explored the role of fires since the area burned by fires each year decreased by about 12% between the early 2000s and the period of 2007 to 2014, according to NASA data. The results show that both fossil fuels and increases in wetland area have contributed to the increase in methane emissions, and that the increase would have been even greater if not for the decrease in the area burned by fire each year.
Most methane molecules in the atmosphere lack identifying characteristics to determine their origin. Thus, identifying methane emission sources is “a detective job involving multiple lines of evidence,” such as gas measurements, chemical analyses, isotopic signatures and land-use observations of land use, which the NASA study combines. The research is published in the journal Nature Communications.
Commenting on the findings, the UNFCCC Secretariat said the world must rapidly transition to wind, solar and other renewable sources of energy, in order to achieve the Paris Agreement’s goal of limiting the global average temperature rise to well below 2°C. [UNFCCC Press Release] [NASA News Story]