The world’s second-largest contributor to global warming after carbon dioxide and a key ingredient in ground-level ozone pollution

Methane is a powerful greenhouse gas and short-lived climate pollutant (SLCP) primarily emitted by human activities. It has an atmospheric lifetime of around 12 years.

Methane severely exacerbates climate change, but also has a number of indirect effects on human health, crop yields and the health of vegetation through its role as a precursor to the formation of tropospheric ozone.

Top Facts 


Methane has a warming impact 86 times stronger than CO2 per unit of mass over a 20 year period. 

12 years

Methane has an atmospheric lifespan of around 12 years. 


Over 60% of methane emissions come from human activity.


Agriculture is the largest human source of methane emissions, responsible for 40%. 

While it has a much shorter lifetime than carbon dioxide (CO2), methane is much more efficient at trapping radiation. Per unit of mass, methane has a warming effect 86 times stronger than CO2 over 20 years. Over a 100-year period methane is 28 times stronger.

Methane’s relatively short atmospheric lifetime and its strong warming potential means that actions to reduce emissions can slow the rate of warming and provide many other societal and environmental benefits within a matter of decades. Maximum possible reductions in methane emissions are essential to limiting atmospheric warming to 1.5°C.  



Methane has anthropogenic (human-caused) and natural sources. More than 90% of global anthropogenic methane emissions stem from three sectors.

The main methane emitting sectors are:

  • Agriculture (40%), including from livestock rearing, animal manure, and rice production.

  • Fossil fuels (35%), including through leakage from natural gas and oil production and distribution systems, and coal mines.

  • Waste (20%), from food and other organic materials left in landfills, open dumps, and wastewater.

Oil and gas operations are the largest source of methane emissions from the fossil fuels sector and there is strong potential to reduce them at little cost.

Methane: Main anthropogenic sources (Mt)
2021. Global Methane Assessment.

Methane emissions trends

2021 saw the largest annual increase in methane emissions since global monitoring began four decades ago. The amount of methane in the atmosphere is increasing at record rates and is projected to increase by up to 13% by 2030

To get on path to holding warming to 1.5°C, the world must reduce baseline methane emissions by 35-40% in 2030.

Global atmospheric methane (Mt)
2021. Global Methane Assessment.

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Global methane action

The 2021 CCAC-UNEP Global Methane Assessment showed that significant action is needed, particularly in this decade, to reduce methane along with all other climate forcers to achieve the 1.5°C target. It also showed that this is achievable. These messages sparked global action, as evidenced by the launch of the Global Methane Pledge (GMP).

Launched in 2021 by the United States, the European Union, and other CCAC partners, the GMP sets a collective target to reduce global methane emissions at least 30% from 2020 levels by 2030, which could eliminate over 0.2˚C warming by 2050.

Methane Impacts

Methane's potent climate warming effect means even small amounts have an outsized impact on climate, environmental, and human health. Not only does methane have a warming effect, it also acts as a precursor for the toxic air pollutant tropospheric ozone. 

Quick action would help limit dangerous climate feedback loops, while simultaneously delivering important health, environmental, and economic benefits from reducing tropospheric ozone. 

Reducing methane emissions would offer immediate and long-lasting multiple benefits not only for the climate, but also agriculture, human and ecosystem health.

Climate Impacts

Methane is second only to CO2 in driving climate change. As carbon dioxide has a long atmospheric lifetime, the results of action on carbon dioxide will take longer to realise. This means reducing methane is a priority to dampen the rate of warming and limit dangerous climate feedback loops such as the melting of the polar ice caps and sea level rise.

Health Impacts

Methane is a key precursor gas of the harmful air pollutant, tropospheric ozone. While methane does not cause direct harm to human health or crop production, ozone is responsible for about 1 million premature respiratory deaths globally. Globally, increased methane emissions are responsible for half of the observed rise in tropospheric ozone levels.

Agriculture Impacts

Through its contribution to producing tropospheric ozone, as well as increasing atmospheric temperatures, methane contributes to staple crop losses of up to 15% per year.

Economic Impacts

Methane’s impacts on climate change and public health contributes to a yearly loss of roughly 400 million hours of work globally due to extreme heat. However, the majority of identified methane abatement controls cost less than the societal benefits - estimated as a benefit of $4,300 per tonne of methane.


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 CCAC 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.

Optimized feed and improved animal health can reduce methane produced by ruminant animals such as cattle, goats and sheep.


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%.

Agriculture sector solutions

Waste Management 

Waste management solutions not only drastically reduce methane emissions but also create jobs and recycle valuable resources. 

Waste sector solutions

Fossil Fuels 

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.

Fossil fuels solutions

Our work

The CCAC funds projects to implement methane policy and mitigation measures around the world. Select a country to find out more.

Latest methane projects