What are superemitter events and why track them? – 08/29/2023 – Environment

When it comes to global warming, everyone usually points to a single culprit: carbon dioxide gas (CO2), produced when we burn fossil fuels such as coal, oil and gas.

But, according to the Intergovernmental Panel on Climate Change (IPCC, its acronym in English), more than 25% of the so-called “greenhouse effect” is caused by another gas: methane (CH4).

You may have heard about the environmental problem caused by cow belching. The gas released is methane, which is also the main component of natural gas, produced by the decomposition or putrefaction of organic matter.

Worrying about cows belching may seem funny, but the truth is that CH4 is a source of great concern for specialists. After all, methane is a gas far more harmful to the environment than carbon dioxide. And when we say “very much,” we are not exaggerating.

The United Nations Environment Program (UNEP) states that “methane is more than 80 times more potent than carbon dioxide in its warming capacity during the 12 years it remains in the atmosphere” .

According to the organism, the reason is that, “due to its chemical structure, methane captures more heat per molecule in the atmosphere than carbon dioxide”.

That’s why the IPCC has highlighted that, to reach the goal of limiting global warming to no more than 2°C compared to the pre-industrial era, we must urgently reduce CH4 emissions by at least a third — and 121 countries have signed up. committed to this goal at the Climate Change Conference in Glasgow, UK, in 2021.

Although livestock is responsible for 33% of methane emissions produced by human activities, cow belching is not the only challenge to achieving this goal.

According to UNEP, agriculture and organic waste generate another 30%. But the biggest source of this gas (35%) is the same one that generates most of the carbon dioxide: fossil fuels. And one of the forms of contamination is through the so-called “super emitters” of methane.

What are superemitters?

Super emitters are equipment, facilities or other infrastructure where massive methane leaks occur, usually due to structural failures.

These massive gas leaks can last for weeks, releasing huge amounts of CH4 into the atmosphere.

And while most super-emissions occur in the oil and gas industry, they can also be produced during coal mining and in larger landfills.

A study led by scientist Thomas Lauvaux, from the Laboratory of Environmental and Climate Sciences at the University of Saclay, France, published in 2022 by the journal scienceestimated that super-emitters released about 8 million tons of methane per year during oil and gas production, between 2019 and 2020.

This volume is equivalent to 8% to 12% of annual global CH4 emissions. But, despite the enormous damage caused to the environment, it is still difficult to reduce these immense losses.

One of the main reasons is that, to stop them, you must first detect them — and tracking methane emissions is complicated, as it is a colorless and odorless gas.

To find and catalog methane losses, UNEP launched, in October 2021, the International Observatory on Methane Emissions (IMEO).

“The great challenge is to know exactly how much [metano] is being issued, where it is coming from and how long it has been issued, so as to be able to reduce emissions to the necessary level,” according to IMEO director Manfredi Caltagirone.

how to detect

Giulia Ferrini works on the formation of IMEO. She told BBC News Mundo (the BBC’s Spanish-language service) that, to find out where the losses occur, “we are currently limited to satellite images, coming from space”.

These images are obtained by special sensors capable of detecting the presence of methane.

The French and US researchers who published the study on super-emitters in the journal science used information obtained by the Sentinel-5 Precursor earth observation satellite, developed by the European Space Agency (ESA).

The satellite took a sensor called the Tropospheric Monitoring Instrument (better known as Tropomi) into space, which was able to detect around 1,800 super methane emissions between 2019 and 2020. But Ferrini warns that the use of satellite images has its limitations.

“It’s important to recognize that satellites can observe some parts of the world better than others and, therefore, the detection of super-emitters can be hindered by the observation capacity of satellites”, she clarifies.

But Ferrini also points out that “as technology advances without stopping, the observation threshold is significantly reduced, which means that we can detect (and therefore combat) smaller emission events. With this, we are equipped to progress beyond the big emitters”.

IMEO’s goal is to “integrate data from diverse sources to ultimately provide the world with a fully transparent set of information.”

For the expert, “only with a solid understanding of where we are in terms of methane emissions, we can develop a clear and solid combat plan to protect our future”.

Ferrini points out that by providing freely accessible information on where large methane losses are produced, “stakeholders in a range of sectors are more motivated to demonstrate their mitigating effects as part of the global fight against climate change.”

Ferrini manages UNEP’s Oil and Gas Methane 2.0 Association. She argues that this sector, where most of the super emissions occur, is the one with the greatest potential to correct them “in an efficient and profitable way”.

“We have evidence that many effective methane reduction strategies would only cost a fraction of industry profits,” she says.