Evaluating LNG’s Carbon Footprint: A comprehensive analysis amid growing global energy demands

The global demand for energy has surged in recent decades, driven by rapid industrialization, population growth, and urbanization, placing unprecedented pressure on the world’s energy systems. This growing need for energy comes at a time of increasing concerns about climate change, prompting urgent calls for cleaner, more sustainable alternatives to traditional fossil fuels. In this context, Liquefied Natural Gas (LNG) has emerged as a significant player, hailed by many as a cleaner option that could help mitigate climate change.

However, as the world leans more on LNG as a potential solution to its energy challenges, a deeper, more nuanced understanding of its environmental implications has become crucial. A new study, titled “LNG and Climate Change: Evaluating Its Carbon Footprint in Comparison to Other Fossil Fuels,” published in the Engineering Science & Technology Journal, aims to provide just that. Authored by Cosmas Dominic Daudu, Adedayo Adefemi, Oladipo Olugbenga Adekoya, Chinelo Emilia Okoli, Olushola Babatunde Ayorinde, and Andrew Ifesinachi Daraojimba, the research presents a comprehensive lifecycle analysis of LNG’s environmental impact and compares it to other conventional fossil fuels such as coal and oil.

The study takes a holistic approach by evaluating LNG’s carbon emissions from every stage of its lifecycle, including extraction, liquefaction, shipping, regasification, and combustion. “While LNG is often viewed as a cleaner alternative to coal and oil due to its lower carbon emissions during combustion, it’s important to recognize that the full environmental impact extends far beyond just the burning phase,” says Olushola Babatunde Ayorinde, one of the key researchers behind the study. “The real challenge lies in evaluating the emissions produced from extraction through to transport and final use, to assess its overall role in mitigating climate change.”

The authors argue that LNG’s reputation as a ‘clean’ energy source is often oversimplified. In their view, a thorough lifecycle analysis is essential to provide policymakers, industry leaders, and environmental advocates with a more complete understanding of LNG’s environmental footprint. “The extraction process, liquefaction, transportation, and regasification are all critical phases where significant emissions can occur,” Ayorinde explains.

The extraction of natural gas is often the first stage where emissions can occur, particularly when unconventional methods such as hydraulic fracturing (fracking) are used. “Fracking can release significant quantities of methane, a potent greenhouse gas, into the atmosphere. This ‘fugitive methane’ is often overlooked in traditional assessments of LNG’s carbon footprint,” Ayorinde points out. The paper emphasizes that even though LNG is touted as a cleaner alternative to coal and oil in terms of carbon dioxide emissions, the methane leakage during extraction can offset some of these benefits, making it a crucial factor in any environmental evaluation.

Liquefaction, the process of cooling natural gas to its liquid form for easier transportation, is another energy-intensive phase in the LNG lifecycle. “Liquefaction requires vast amounts of energy, and depending on the energy sources used, this can lead to significant carbon emissions,” the researchers note. “The carbon intensity of LNG production can vary significantly depending on the efficiency of liquefaction technologies and the energy mix in the region where it’s produced.”

The study underscores the importance of technological innovations in the liquefaction process. “More energy-efficient liquefaction methods and the use of cleaner energy sources could substantially reduce LNG’s overall emissions,” Ayorinde adds. “However, significant investments are needed to upgrade current technologies and ensure that LNG’s carbon footprint remains as low as possible.”

Once LNG is liquefied, it is typically transported over long distances by specialized tankers, which introduces another layer of emissions. “Shipping LNG across large distances requires significant energy, often using fossil fuels such as diesel or heavy fuel oil,” the paper explains. While the latest generation of LNG carriers has become more fuel-efficient, this process still contributes substantially to LNG’s carbon footprint.

“Transportation is often an overlooked phase when assessing LNG’s environmental impact,” says Ayorinde. “The energy used in shipping LNG across the globe is a major contributor to its overall emissions, and it is one of the areas where there is room for substantial improvement.” He notes that advancements in fuel efficiency, as well as the use of cleaner fuels for shipping, could help mitigate the emissions associated with LNG transport.

After transportation, LNG is regasified at its destination for use in power generation, industry, or residential consumption. While regasification is a less energy-intensive process than liquefaction, it still requires energy, which is often drawn from fossil fuel sources. “While the emissions from regasification are smaller compared to the other phases, they should still be factored into the overall lifecycle analysis,” Ayorinde asserts.

When LNG is finally combusted as a fuel, it emits far less carbon dioxide compared to coal and oil. “At the point of combustion, LNG is significantly cleaner than both coal and oil, emitting up to 30% less carbon dioxide than oil and around 50% less than coal,” the researchers write. “This is why LNG has become a key player in the global energy transition, but its advantages at the combustion stage need to be weighed against the emissions produced earlier in the lifecycle.”

The study also compares LNG’s environmental impact with that of other fossil fuels like coal and oil. While coal and oil are known for their high carbon emissions during combustion, LNG’s emissions can vary depending on the technologies used throughout its lifecycle. “Coal and oil typically have much higher carbon intensity when burned, but LNG’s production, liquefaction, and transportation can sometimes lead to emissions that bring it closer to the emissions from coal and oil than commonly assumed,” Ayorinde explains.

The study argues that LNG should not be considered a permanent solution to the climate crisis. “LNG may be a cleaner option in the short term, especially as a replacement for coal and oil, but it is not a long-term solution,” says Ayorinde. “We need to transition to truly sustainable energy sources, such as wind, solar, and hydrogen, to reduce global dependence on fossil fuels.”

As LNG continues to grow in importance, technological advancements will play a key role in reducing its carbon intensity. “Technologies such as carbon capture and storage (CCS), advanced liquefaction technologies, and more efficient LNG carriers can reduce emissions significantly,” Ayorinde says. “However, these technologies need to be deployed on a large scale if LNG is to live up to its potential as a lower-carbon energy source.”

Recent innovations in carbon capture and storage could provide a solution to some of LNG’s environmental challenges. “If we can capture the CO2 emissions produced during liquefaction and combustion, LNG could become a much more viable option in the fight against climate change,” the paper suggests. “But for this to happen, there must be continued investment in CCS technologies and their integration into LNG operations.”

The study also emphasizes that the environmental impact of LNG varies significantly depending on regional and geopolitical factors. “The carbon footprint of LNG depends heavily on where it is sourced and the technologies employed in its production,” Ayorinde notes. “In some regions, LNG production relies on cleaner energy sources, which can lower its overall emissions. In others, particularly where coal is still used in power generation, the carbon footprint can be much higher.”

The researchers argue that policy decisions related to LNG should be tailored to local contexts. “Energy policies need to take into account regional variations in energy production, technological capabilities, and environmental conditions,” Ayorinde explains. “What works in one region may not work in another, and the carbon footprint of LNG should be evaluated on a case-by-case basis.”

Looking ahead, the future of LNG in a low-carbon energy system remains uncertain. “LNG may play a role in the transition to a more sustainable energy future, but it should not be viewed as a permanent solution,” Ayorinde warns. “It is crucial that the world continues to invest in renewable energy sources and energy-efficient technologies to reduce dependence on fossil fuels.”

The study concludes that while LNG has the potential to serve as a bridge fuel in the energy transition, it is not without its environmental challenges. “LNG has a role to play in the global energy transition, but it is important to understand its full lifecycle emissions and the technological innovations needed to reduce them,” Ayorinde asserts. “As the world strives to reduce greenhouse gas emissions, LNG should be viewed as one part of a much larger solution.”

By providing a comprehensive analysis of LNG’s carbon footprint, the study offers policymakers, industry leaders, and environmental advocates a deeper understanding of the energy source’s environmental impact. “This research is intended to help guide informed decision-making in the energy sector, ensuring that LNG is used in the most sustainable way possible,” says Ayorinde.

As the world moves toward a more sustainable energy future, LNG’s role will continue to evolve. The findings of this study contribute valuable insights into the ongoing debate over how best to balance global energy needs with climate change mitigation efforts.