Tracking methane emissions for mitigation-

Subject: Science and Technology

Context-

Methane-monitoring satellites show that landfills contributed to more than 25% of methane emissions in Mumbai and 6% in Delhi.

Methane emission-

Methane is a short-lived climate forcer (SLCF), a compound that warms or cools the Earth’s climate over shorter time scales – from days to years – than greenhouse gases like carbon dioxide, whose climatic effect lasts for decades, centuries or more.
Methane has a lifetime in the atmosphere of about ten years. But per molecule, it’s a much more potent greenhouse gas over that period.
So it’s responsible for a large part of the warming that we’re experiencing today.
The Global Methane Assessment 2021 states that the atmospheric concentration of methane has more than doubled since pre-industrial times.
Methane is second only to carbon dioxide (CO2) in driving climate change.
Limiting warming to 1.5⁰C or likely 2⁰C requires deep, rapid, sustained reductions of other greenhouse gases, such as methane, alongside rapid reductions of carbon dioxide emissions to net zero.

Sources of Methane emission-

Methane is produced by the breakdown or decay of organic material and can be introduced into the atmosphere by either natural processes – such as the decay of plant material in wetlands, the seepage of gas from underground deposits or the digestion of food by cattle – or human activities – such as oil and gas production, rice farming or waste management.
More than half of global methane emissions stem from human activities in three sectors: fossil fuels (35% of human-caused emissions), waste (20%) and agriculture (40%).

Urban landfills generate emissions-

Scientifically any landfill which is more than six metres deep has the potential to generate methane.
Methane-monitoring satellites show that landfills contributed to more than 25% of methane emissions in Mumbai and 6% in Delhi.
Scientists at IITM, Pune found that microbial and fossil fuel emissions are two major methane sources in Pune.
- Natural gas was the dominant sector in the fossil fuel sector, while the waste sector was the major segment in microbial emissions.
- In Pune, landfill emissions are very high with respect to other sources.
- It could be methane in CNG stations, CNG pipeline, and CNG gas networks, and it needs to be investigated
Landfills in Kolkata (Dhapa), Mumbai (Deonar) and Delhi (Bhalswa and Ghazipur) are often been in the news for landfill fires.
It causes greenhouse gas emissions.
It also leads to local pollution in the area.
In wintertime, the air rises up slowly because of low temperatures.
So any smoke or any pollution coming out can persist in the lower layers for longer periods.

Why do these landfills become a hotspot of methane emissions?

Because the landfills in India are not scientifically engineered during inception.
They don’t have bottom liners and gas harvesting systems during the development of the landfill.
Collection and recovery of landfill gas (methane emissions) is a technical challenge.
Also, there is no dedicated organisation to maintain the history of waste disposal in landfills, which leads to an overestimation of landfill gases.
The overestimation of landfill gas concentration led to claiming of more carbon credits in Mumbai’s Gorai landfill closure and gas capture project, which was implemented in the Clean Development Mechanism framework, the world’s largest carbon offset programme, established under the Kyoto Protocol.

Methane emission tracking-

The TROPOMI instrument on board the European Space Agency’s Copernicus Sentinel-5 Precursor satellite and GHGSat’s space-based emissions monitoring systems are used to detect, locate, and quantify emissions from strong methane point sources around the world.
Using this approach, they spotlighted methane emissions hotspots in Buenos Aires, Delhi, Lahore, and Mumbai.

Emission mitigation-

Landfills are potantial targets for emission mitigation.
MethaneSAT-
- It is a planned American-New Zealand space mission currently scheduled for launch in 2023.
- The mission is planned to be an Earth observation satellite that will monitor and study global methane emissions in order to combat climate change.
- It aims to track not only the rate of methane emissions and location but also how those emissions are changing.
- The mission is jointly funded and operated by the Environmental Defense Fund (EDF), an American non-governmental organization, and the New Zealand Space Agency.
- It marks New Zealand’s first space science mission.
Such observations will be useful to initiatives such as the International Methane Emissions Observatory (IMEO).
The International Methane Emissions Observatory (IMEO) was launched at the G20 Summit, on the eve of the COP26 UN climate conference in
IMEO will bring global reporting on methane emissions to an entirely different level, ensuring public transparency on anthropogenic methane emissions.
IMEO will initially focus on methane emissions from the fossil fuel sector, and then expand to other major emitting sectors like agriculture and waste.

Global Methane Pledge

The Global Methane Pledge was launched at the ongoing UN COP26 climate conference in Glasgow.
It is an effort led jointly by the United States and the European Union.
Methane is the second-most abundant greenhouse gas in the atmosphere, after carbon dioxide, and, therefore, pledges related to cutting down its emissions are significant.
The pledge was first announced in September 2021by the US and EU, and is essentially an agreement to reduce global methane emissions. One of the central aims of this agreement is to cut down methane emissions by up to 30 per cent from 2020 levels by the year 2030.
Among the signatories is Brazil — one of the five biggest emitters of methane, which is generated in cows’ digestive systems, in landfill waste and in oil and gas production.
- Three others —China, Russia and India — have not signed up.
- Australia has said it will not back the pledge.
According to the latest Intergovernmental Panel on Climate Change report, methane accounts for about half of the 1.0 degrees Celsius net rise in global average temperature since the pre-industrial era.