COP26: Anthropogenic Methane Emissions

The Global Methane Pledge at the COP26 Summit in Glasgow was led by the US and the EU, who gathered other 103 countries that combined, account for 46 percent of global methane emissions and represent 70 percent of the world economy. They included several cattle-rich countries like Brazil, Canada, Argentina, and New Zealand.  But China, Russia, and India, which together comprise 35 percent of global methane emissions, did not join the coalition.

Global average temperatures are roughly 1.1°C warmer today than in pre-industrial times and it is an indisputable fact that greenhouse gas (GHG) concentrations in the atmosphere, caused by human activities such as burning fossil fuels, destruction of carbon sinks due to deforestation including agricultural and waste sources, are indeed responsible for warming the globe – atmosphere, ocean, and land.  A GHG is a gas that absorbs and emits radiant energy within the thermal infrared range, causing the greenhouse effect.  Oxford dictionary defines:

  • Greenhouse effect as the trapping of the sun’s warmth in a planet’s lower atmosphere, due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet’s surface.

Methane (CH4) is a GHG which has caused about 0.5°C of global warming, according to the latest assessment by the Intergovernmental Panel on Climate Change (IPCC). Each molecule added to the atmosphere is about 26 times more potent at warming than a carbon dioxide (CO₂) molecule, but only remains in the atmosphere for about a decade. CH4 leaks from oil and gas wells, landfills and is belched out by livestock.  The IPCC also found methane levels in the air are now higher than at any point in the past 800,000 years and are tracking close to the high emission scenarios outlined in its previous assessment in 2013.

As far as the austerity of methane is concerned – one tonne of CH4 is equivalent to 30 tonnes of CO2.

According to scenarios analyzed by the IPCC, global CH4 emissions must be reduced by between 40–45 percent by 2030 to achieve least cost-pathways that limit global warming to 1.5° C this century, alongside substantial simultaneous reductions of all climate forcers including CO2 and short-lived climate pollutants.

The Global Methane Assessment shows that human-caused methane emissions can be reduced by up to 45 percent this decade.  Such reductions would avoid nearly 0.3°C of global warming by 2045 and would be consistent with keeping the Paris Climate Agreement’s goal to limit global temperature rise to 1.5 degrees Celsius (1.5˚C) within reach.  The Global Assessment also disclosed that:

  • As methane is a key ingredient in the formation of ground-level ozone (smog), a powerful climate forcer and dangerous air pollutant, a 45 percent reduction would prevent 260 000 premature deaths, 775 000 asthma-related hospital visits, 73 billion hours of lost labour from extreme heat, and 25 million tonnes of crop losses annually. 

Here is a graph which is designed to illustrate the configuration of global GHG emissions:

Here is an explanation of each category of global emissions:

  • CO2 GLOBALEMISSIONS: A combination of CO2 emissions account for 76 percent of total global emissions which caused by the use of fossil fuels, industrial processes, forestry and other use of land. Fossil fuel use is the primary source of CO2 emissions. CO2 can also be emitted from direct human-induced impacts on forestry and other land use, such as through deforestation, land clearing for agriculture, and degradation of soils. Likewise, land can also remove CO2 from the atmosphere through reforestation, improvement of soils, and other activities;
  • CH4 GLOBAL EMISSIONS: Agricultural activities, waste management, energy use, and biomass burning all contribute to CH4 emissions. These emissions represent 16 percent;
  • N2O – NITROUS GLOBAL OXIDE EMISSIONS: Agricultural activities, such as fertilizer use, are the primary source of N2O emissions. Fossil fuel combustion also generates N2O; and
  • F-GASSES GLOBAL EMISSIONS: Industrial processes, refrigeration, and the use of a variety of consumer products contribute to emissions of F-gases, which include hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6).

A recent report published by the UN Environment Programme on the subject of Benefits and Costs of Mitigating Methane Emissions discloses the fact that anthropogenic global methane emissions represent roughly 60 percent whereas natural global methane emissions account for 40 percent of the total global methane emissions:

This article is dedicated to Anthropogenic Methane Emissions.

Out of 60 percent of total global methane emissions generated by anthropogenic sources, more than 90 percent originate from the following three sectors:

  • Agriculture Sector: Emissions from enteric fermentation and manure management represent roughly 32 percent of global anthropogenic emissions. Rice cultivation adds another 8 per cent to anthropogenic emissions.  Agricultural waste burning contributes about less than 1 percent.
  • This sector generates a total of 140 Million Tonnes total Global Anthropogenic Methane Emissions every year:
    • Fermentation and Manure Management 110 Million Tonnes Emissions
    • Rice Cultivation 30 Million Tonnes Emissions
  • Fossil Fuels Sector: This sector releases anthropogenic emissions during oil and gas extraction, pumping and transport of fossil fuels accounts for roughly 23 percent of all anthropogenic emissions, with emissions from coal mining contributing 12 percent.
  • This sector generates a total of 125 Million Tonnes total Global Anthropogenic Methane Emissions every year:
    • Oil and Gas Extraction and Pumping & Transport 83 Million Tonnes
    • Coal Mining 83 Million Tonnes
  • Waste Sector: landfills and waste management represents the next largest component making up about 20 percent of total global anthropogenic methane emissions.
  • This sector generates a total of 67 Million Tonnes Global Methane Emissions every year:

Here is a graph designed to summarize the total global anthropogenic methane emissions generated by all three sectors each year – Agriculture, Fossil Fuels, and West:

Here is a chart which is designed to explain the contribution of major 12 countries around the world to global anthropogenic methane emissions each year:

The top 4 countries from the char presented above contribute 49.5 percent of the total global anthropogenic methane emissions each year.

Here is a graph which is designed to highlight the total anthropogenic methane emissions and associated percentage for all 12 countries in the world:

Here is another graph which illustrates anthropogenic total global methane emissions in all three sectors:

According to Global Methane Assessment based on the current available measures, the total global anthropogenic methane emissions could be reduced as much as 45 percent by 2030 which is estimated to be 180 Mt/Yr.  This is consistent with the scenarios analyzed by the IPCC as global methane anthropogenic emissions must be reduced by between 40-45 percent by 2030 to achieve least cost-pathways that limit global warming to 1.5° C this century, alongside substantial simultaneous reductions of all climate forcers including CO2 and short-lived climate pollutants.

The good news is that there are readily available targeted measures that can help reduce 2030 global anthropogenic methane emissions by 30 per cent, around 120 Mt/yr.  Nearly half of these technologies are available to the fossil fuel sector in which it is relatively easy to reduce methane emissions at the point of emission and along production/transmission lines.  There are also available targeted solutions in the waste and agricultural sectors. The bad news is that the current targeted solutions alone, however, are not enough to achieve 1.5o C consistent mitigation by 2030.

The reality is that in order to achieve that, additional measures must be deployed, which could reduce 2030 global methane emissions by another 15 per cent, about 60 Mt/Yr. Here are some additional approaches:

  • Roughly 60 percent, around 75 Mt/Yr, of available targeted measures have low mitigation costs and just over 50 per cent of those have negative costs – the measures pay for themselves quickly by saving money; and
  • Low-cost abatement potentials range from 60–80 per cent of the total for oil and gas, from 55–98 percent for coal, and approximately 30–60 per cent in the waste sector.

This report also identified the fact that the greatest potential for negative cost abatement is in the oil and gas subsector where captured methane adds to revenue instead of being released to the atmosphere.

It also must be kept in mind that the mitigation potential in different sectors varies between countries and regions. For instance:

  • The largest potential in Europe and India is in the waste sector;
  • In China from coal production followed by livestock;
  • In Africa from livestock followed by oil and gas;
  • In the Asia-Pacific region, excluding China and India, it is coal and waste;
  • In the Middle East, North America and Russia/Former Soviet Union it is from oil and gas; and
  • In Latin America it is from the livestock subsector.

A majority of these major abatement potentials can be achieved at low cost, less than US$ 600 per tonne of methane, especially in the waste sector and the coal subsector in most regions and for the oil and gas subsector in North America. Fortunately, mitigation potential from all measures is expected to increase between 2030 and 2050, especially in the fossil fuel and waste sectors.

A host of philanthropies have committed $328 million to support methane mitigation strategies as part of the Global Methane Pledge.

Jonathan Wilkinson, Minister of Environment and Climate Change, announced Canada’s support for the Global Methane Pledge, which aims to reduce global methane emissions by 30 percent below 2020 levels by 2030. In support of the Pledge and the goals in Canada’s climate plan, Minister Wilkinson also announced Canada’s commitment to developing a plan to reduce methane emissions across the broader Canadian economy and to reducing oil and gas methane emissions by at least 75 percent below 2012 levels by 2030. Canada is the first and only country to support the Pledge and the 75 percent goal, and this approach will include regulations.  Moving forward, Canada will mobilize and work with the energy sector, provinces, territories, Indigenous Peoples, and other stakeholders in developing our approach.

Ottawa, Ontario, Canada 31 December 2021