Production of New Methane by Microbes

May 1, 2024

GS Paper III Environment and Ecology

Context:

Recently, an intensive modeling study has found that microbes have been the biggest sources of methane in the atmosphere, not the burning of fossil fuels.

More on News:

Methane emissions from fossil fuels declined between 1990 and the 2000s and have been stable since, whereas microbes have been producing more methane.
At the U.N. climate talks in 2021, member countries launched the ‘Global Methane Pledge’ to cut the gas’s emissions and slow the planet’s warming.

Need for Local Data:

Data Mismatch: This recent data is mismatched with two emissions inventories, called EDGAR and GAINS.
- EDGAR: It had reported that methane emissions from oil and natural gas exploration had increased between 1990 and 2020.
- GAINS: It had recorded a large “unconventional” rise in emissions since 2006.
Reason of Mismatch: One possible reason could be an increase in cattle-rearing in Latin America and more emissions from waste in South and Southeast Asia, Latin America, and Africa. Also, the number of wetlands worldwide had increased.
Most studies which use satellites cannot measure the actual [changes over time] of methane. Satellite data is interpreted using models and thus are prone to uncertainties.

Methane:

A Greenhouse Gas: Methane is the second most abundant anthropogenic greenhouse gas after carbon dioxide (CO2) but it warms the planet more.
- Over a century, methane has a global warming potential 28-times greater than CO2, and even higher over shorter periods like two decades.
Its Sources: Scientists are increasingly recognising various sources of methane, most of which fit in two categories: biogenic and thermogenic.
- Thermogenic: When fossil fuels such as natural gas or oil are extracted from deep within the earth’s crust, thermogenic methane is released.
- Biogenic: This methane comes from microbial action.
  - Both biogenic and thermogenic activities produce different isotopes of methane. Tracking the isotopes by carbon-13 is a way to track which sources are the most active.
    - If there are fewer carbon-13 atoms than a certain level in a group of 1,000 methane molecules, the methane is from a biological source.
    - If the methane is from thermogenic sources, such as trapped fossil fuels or geological activities, there will be more carbon-13 atoms in 1,000 molecules.
      - Carbon-13 atoms of this carbon isotope have 13 nucleons: 6 protons + 7 neutrons
Action Required: To reduce methane, anthropogenic activity should be first controlled.
- Anthropogenic activity includes waste and landfills, rice fields, enteric fermentation, oil and gas, and coal.

About Methane producing Bacterias:

Methanogens: The microbes that produce methane are archaea (single-celled microorganisms) distinct from bacteria and eukaryotes and are called methanogens.
Surviving Condition: They thrive in oxygen-deficient environments, such as the digestive tracts of animals, wetlands, rice paddies, landfills, and the sediments of lakes and oceans.
Significance: Methanogens play a crucial role in the global carbon cycle by converting organic matter into methane.
- While methane is a potent greenhouse gas, its production by methanogens is an essential part of natural ecosystems.
  - But human activities like agriculture, dairy farming, and fossil fuel production have further increased methane emissions.

Initiatives to Tackle Methane Emissions:

Global:
- Methane Alert and Response System (MARS): To integrate data from a large number of existing and future satellites that have the ability to detect methane emission events anywhere in the world, send out notifications to the relevant stakeholders to act on it.
- Global Methane Pledge: It has its origin at the Glasgow climate conference (UNFCCC COP 26) in 2021, to cut methane emissions by at least 30% by 2030 from the 2020 levels.
  - India is not a part of the Global Methane Pledge.
- Global Methane Initiative (GMI): It is an international public-private partnership focused on reducing barriers to the recovery and use of methane as a clean energy source.
India:
- Harit Dhara (HD): By Indian Council of Agricultural Research (ICAR) to cut down cattle methane emissions by 17-20% and can also result in higher milk production.
- India Greenhouse Gas Program: It is led by WRI India (non-profit organization), Confederation of Indian Industry (CII) and The Energy and Resources Institute (TERI) is an industry-led voluntary framework to measure and manage greenhouse gas emissions.
- National Action Plan on Climate Change (NAPCC): It was launched in 2008 to create awareness among the representatives of the public, different agencies of the government, scientists, industry and the communities on the threat posed by climate change and the steps to counter it.
- Bharat Stage-VI Norms: India shifted from Bharat Stage-IV (BS-IV) to Bharat Stage-VI (BS-VI) emission norms.