Methane

Methane is a powerful greenhouse gas emitted by human activities such as leakage from natural gas systems and the raising of livestock, as well as by natural sources such as wetlands. It has a direct influence on climate, but also a number of indirect effects on human health, crop yields and the quality and productivity of vegetation through its role as an important precursor to the formation of tropospheric ozone.

Methane is a short-lived climate pollutant with an atmospheric lifetime of around 12 years. While its lifetime in the atmosphere is much shorter than carbon dioxide (CO₂), it is much more efficient at trapping radiation. Per unit of mass, the impact of methane on climate change over 20 years is 86 times greater than CO₂; over a 100-year period it is 28 times greater.

Multiple studies have demonstrated that a selection of measures to cut methane emissions can reduce near-term warming of the climate, increase crop yields and prevent premature deaths.

Atmospheric methane concentrations have grown as a result of human activities related to agriculture, including rice cultivation and ruminant livestock; coal mining; oil and gas production and distribution; biomass burning; and municipal waste landfilling. Emissions are projected to continue to increase by 2030 unless immediate action is taken.

In agriculture, rapid and large scale implementation of improved livestock feeding strategies can reduce of 20% of global methane emissions by 2030, while full implementation of intermittent aeration of continually flooded rice paddies (known as alternate wetting and drying cultivation) could reduce emission from rice production by over 30%.

Emissions from coal mining and the oil and gas sector could be reduced by over 65% by preventing gas leakage during transmission and distribution, recovering and using gas at the production stage, and by pre-mine degasification and recovery of methane during coal mining.

Methane is generally considered second to carbon dioxide in its importance to climate change. The presence of methane in the atmosphere can also affect the abundance of other greenhouse gases, such as tropospheric ozone, water vapor and carbon dioxide.

Recent research suggests that the contribution of methane emissions to global warming is 25% higher than previous estimates.>

Methane is a key precursor gas of the harmful air pollutant, tropospheric ozone. Globally, increased methane emissions are responsible for half of the observed rise in tropospheric ozone levels.

While methane does not cause direct harm to human health or crop production, ozone is responsible for about 1 million premature respiratory deaths globally. Methane is responsible for about half of these deaths.

The relatively short atmospheric lifetime of methane, combined with its strong warming potential, means that targeted strategies to reduce emissions can provide climate and health benefits within a few decades.

The Coalition supports implementation of control measures that, if globally implemented by 2030, could reduce global methane emissions by as much as 40%. Several of these emission reductions could be achieved with net savings, providing quick benefits for the climate as well as public health and agricultural yields.

  
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