Over the past decade, natural gas has been touted as the perfect ‘bridge fuel’ as the world transitions to low-carbon fuels. That appears pretty straightforward considering natural gas emits almost 50% less CO2 than coal when burnt as fuel. However, recent studies have discovered that leakages from natural gas infrastructure occur at much higher rates than previously thought, potentially denting the fuel’s green credentials.
A new peer-reviewed analysis in the journal Environmental Research Letters finds that relatively small amounts of methane--the primary constituent of natural gas--can drive up the industry's emissions to equal the effects of coal thanks to methane’s much more potent greenhouse gas effect compared to CO2. Scientists from NASA, Harvard University and Duke University also contributed to the paper.
"This analysis compares gas and coal at varying methane leakage rates. We find that very small methane leakage rates from gas systems rival coal's greenhouse gas emissions," said Deborah Gordon, co-author of the analysis and a senior principal at the environmental group RMI.
“The study has found that even leaks amounting to as low as as low as 0.2% of the methane in the country's gas production and supply system are enough to do as much damage as burning coal. That’s highly alarming considering that recent surveys have found leak rates far above that, of "0.65% to 66.2%."
Leaky Infrastructure
Leaky oil and gas infrastructure have been playing an outsized role in climate change by spewing out far more quantities of an even more potent greenhouse gas into the atmosphere than earlier thought.
Three years ago, Reuters reported that satellites by the European Space Agency had detected huge plumes of methane leaking from the 2,607-mile-long Yamal pipeline that transports natural gas from Siberia to Europe and operated by Gazprom. Using the satellite data, energy consultancy Kayrros estimated that one leak was spewing out a staggering 93 tonnes of methane every hour, equal to the amount of CO2 emitted by 15,000 cars in the U.S. in a whole year. A second leak on the same pipeline was nearly as egregious, gushing 17 tonnes of the colorless and odorless gas every hour.
Those discoveries suggest that we have been unfairly blaming mud volcanoes and natural oil and gas seepages for the sharp increase in atmospheric methane and that our drilling activities could in fact be directly responsible.
Currently, there isn’t much methane in the atmosphere--only 1,920 parts per billion, or about two cups of water inside a standard Olympic-size swimming pool. In contrast, CO2 levels in 2023 were measured at 417 parts per million (ppm), making it 217x more abundant than methane in the atmosphere. Although methane does not usually get the same bad rap that carbon dioxide does, it’s actually a far more potent greenhouse gas, over 80x more powerful at warming the earth than CO2 over 20 years and 28x more powerful on a 100-year timescale. Methane’s chemical shape is what makes it remarkably effective at trapping heat, and adding just a little more of the gas into the atmosphere can have profound effects on how quickly the planet warms.
The bad news: Methane levels have increased sharply over the past four decades, and are now responsible for about one-sixth of the total energy imbalance that is causing global warming.
Source: Climate.gov
Oil and gas companies in the spotlight
Methane typically lasts only about a decade before it’s cycled out--a blip, really, compared to the centuries that a CO2 molecule can last. However, methane has many sources, meaning the atmospheric load is constantly replenished.
About 40% of the earth’s methane is thought to come from natural sources including wetlands and bogs. Many microbes that thrive in oxygen-deprived ecosystems like waterlogged wetland soils spew out methane instead of CO2, which leaks directly into the atmosphere. Some methane also seeps out of the ground in areas with high volcanic activity as well as naturally near some oil and gas deposits.
Human activities, however, are by far the biggest source of methane on our planet, contributing 60% of new emissions every year. Our 1.4 billion or so domesticated bovines as well as oil and gas drilling activities are responsible for much of the damage.
Cows and other grazing animals host trillions of gut-filling hitchhikers that help them break down tough grasses to access the nutrients. These anaerobic microbes account for about a quarter of the world’s annual methane budget. Other agricultural endeavors such as rice paddies, landfills and sewage treatment centers also produce significant amounts of methane.
It was previously estimated that the energy sector contributes ~25% of the world’s methane emissions. However, the latest revelation implies that these estimates are highly conservative. Indeed, the latest findings are backed by a 2015 study that found that U.S. oil and gas supply chains produce ∼60% more methane than estimates by the Environmental Protection Agency (EPA).
Hitherto, most industries have estimated greenhouse gas emission by largely relying on paper-based calculations of what’s pouring out of smokestacks and tailpipes, as well as based on the amount of energy consumed by end users. But improvements in satellite technology are allowing researchers to actually stress test the data--and so far it’s revealing that oil and gas companies are more culpable than we thought.
Many countries have enacted strict rules about how much methane leakage is allowed. Unfortunately, these rules have mostly proven difficult to enforce. The latest revelation is likely to heap additional pressure on embattled energy companies to track their methane emissions and plug them.
BP and Royal Dutch Shell have invested in satellite companies or signed monitoring deals to help track and plug their methane leaks--this might soon become mandatory for all oil and gas companies involved in drilling and transportation activities.
ADVERTISEMENT
A study published in Nature Energy in May revealed that the U.S. Oil Patch is home to tens of thousands of inactive offshore oil and gas wells that remain unplugged, posing the risk of possible leaks into the ocean. The study estimates that whereas plugging and abandoning these wells could minimize their environmental risk, the exercise would cost the industry a hefty $30 billion. There are more inactive, non-producing wells in the Gulf of Mexico coastal waters in Louisiana, Texas and Alabama that have not been plugged and abandoned than currently active wells in this region.
It also means that companies operating in the region risk clashing with the regulators sooner rather than later.
The U.S. pipeline regulator unveiled new rules aimed at lowering methane leaks from the vast network of 2.7 million miles of natural gas pipelines in the country. The proposal issued Friday by the Transportation Department's Pipeline and Hazardous Materials Safety Administration could "significantly improve the detection and repair of leaks from gas pipelines... deploy pipeline workers across the country to keep more product in the pipe, and prevent dangerous accidents."The agency estimates the new rules could potentially eliminate 1 million metric tons of methane emissions by 2030, the equivalent of emissions from 5.6 million cars.
By Alex Kimani for Oilprice.com
More Top Reads From Oilprice.com:
- Japan Wants A Global Emergency Natural Gas Reserve
- U.S. Shale Challenges OPEC With Record Production In 2023
- Carbon Prices Set To Fall As Europe Speeds Up Energy Transition
Dr Mamdouh G Salameh
International Oil Economist
Global Energy Expert