LNG Emissions

LNG emissions: managing CO2 through the gas value chain

Natural gas and liquefied natural gas (LNG) are vital components of energy systems around Asia. Gas has a long-standing role in providing energy security for key regional and global economies such as Japan, South Korea, Thailand and Singapore. It is also of increasing importance in providing emerging nations in Asia with a cleaner-burning alternative to coal for power generation.

Because natural gas is a fossil fuel, it has an emissions profile that requires monitoring and management. Asia lacks gas resources to be self-sufficient, especially as existing fields deplete, so most of its supply must be sourced from outside the region as LNG imports.

Emissions and power generation

In the context of power generation, lifecycle emissions can be considered to be greenhouse gases released during production, transportation and consumption of any fuel. In the case of LNG, emissions occur during the processes of extraction, transport to a liquefication facility, liquefication, shipping, regasification, storage, end-use transport and then combustion.

Greenhouse Gases

Greenhouse gases are those which trap heat in the atmosphere and include carbon dioxide, methane, nitrous oxide and a variety of fluorinated gases. Carbon dioxide is the primary greenhouse gas produced by human activities and the emissions contributions of all greenhouse gases are usually converted to a carbon dioxide equivalent to provide a standardised point-of-reference.

Nations around the world have made commitments to reducing greenhouse gas emissions, which are outlined in each country’s Nationally Determined Contributions.

Emissions of natural gas as a fuel

Natural gas and liquefied natural gas are valued globally for the fact they produce far fewer emissions during combustion than other fossil fuels.

According to the International Energy Agency, switching out for coal for gas results in 50 per cent fewer emissions when used to produce electricity and 33 per cent fewer emissions when used to generate heat.

With coal accounting for more than 50 per cent of Asia’s overall electricity generation and consumption continuing to rise in emerging Asia, natural gas will be critical to the region’s aspirations to reduce emissions over the next few decades. Gas can provide cleaner power generation for energy security as nations grow their investments in renewable energy.

CO2 emissions factors for fuels used in electricity generation

One of the prime examples of the benefits of coal-to-gas switching can be seen in the United States, where natural gas has now overtaken coal as the largest source of electricity generation. Data from the United States Energy Information Administration (EIA) shows that CO2 emissions from US power generation decreased by 819 million tonnes between 2005 and 2009. Of this reduction, 65 per cent could be attributed to shifting from coal-fired power to generation from natural gas.

Emissions in the LNG value chain

Managing emissions throughout the LNG value chain is a key challenge for gas producers and their customers. This includes fugitive methane emissions that can occur when gas is being transported through pipeline and during shipping of LNG. While methane has a shorter atmospheric lifespan than carbon dioxide, it traps more heat per molecule because of its structure. Because methane is colourless and odorless, detecting methane emissions and pinpointing the source-of-origin is difficult.

Methane emissions

There is strong recognition within the global gas industry of the need to continually step up and refine efforts to detect methane emissions and, wherever feasible, to mitigate and eliminate them. The use of satellites, drones, aircraft and fixed sensors is helping gas producers detect and respond to methane emissions more quickly, while aerial LIDAR – laser image, detecting and ranging – can also be employed to highlight methane plumes and track emissions back to their source.

A range of collaborative programs have emerged in Asia, aimed specifically at tackling methane emissions associated with gas/LNG. These include the CLEAN initiative, a collaboration between Japan and Korea that focuses on collection information from LNG producers to inform best practice in methane emission management and reduction. The ASEAN Centre for Energy has also launched a Methane Leadership Program that has attracted participants from around the region, including the Asia Natural Gas and Energy Association (ANGEA).

LNG producers are also working to reduce emissions through the value chain by using renewable energy to power operations, developing alternative lower-emission fuels (such as ammonia) to decarbonise shipping and investing in carbon capture and storage (CCS) technology. CCS can be used to reduce emissions from both the production and consumption of gas. Improved efficiency and reliability of the turbines in gas-fired power plants and modernisation of LNG carriers are other contributors to reduced emissions.

Comparing the use of LNG in Asia to coal

A 2024 study by Berkley Research Group found that lifecycle greenhouse gas emissions for LNG produced in the United States and exported for use in Asia were less than half of those produced by coal. The research showed US LNG imported and consumed by South Korea, India, Taiwan, Japan and China had an average greenhouse gas emissions intensity of 507kg CO2e/Mwh compared to the average coal figure of 1077kg CO2e/Mwh.

The research, undertaken over a four-year period, tracked lifecycle emissions of US LNG from upstream production, through liquefication, shipping and then use in power generation. It used rigorous, analytic lifecycle assessment methodology and continuously updated data and information from the best available sources.

Notably, the study found combustion of US LNG produced nearly three times fewer emissions than coal used in the focus countries.

Similarly, 2025 analysis by S&P Global Commodity Insights found that LNG from Australia, the US and Qatar – the world’s three biggest exporters – had 47 per cent lower average lifecycle carbon intensity than coal when used in power generation in Japan, the Philippines and Vietnam.

LNG as part of Asia’s energy transition

Throughout Asia, countries are working to shift to lower-carbon energy sources in order to progress emissions reduction targets, including net zero. Given the context of coal use in Asia – no other region in the world is so reliant on it – it is imperative that nations can affordably access alternative sources of energy security.

Because of its lower emissions profile, particularly in the combustion phase of power generation, natural gas is a logical choice for Asia. And because there are insufficient regional gas resources to meet demand, LNG imports are an essential part of Asia’s energy landscape. According to Shell’s LNG Outlook 2022, if only 20 per cent of Asia’s coal-fired power was replaced with gas, avoided CO2 emissions would total more than 680 million tonnes a year.

Where does Asia’s LNG come from?

The 2025 Annual Report of the International Group of Liquefied Natural Gas Importers (GIIGNL) showed that Asia received 18% of its LNG from the Pacific Basin, with 28% coming from the Middle East and 54% coming from the Pacific Basin. The three biggest single sources of LNG imports for Asia in 2024 were Australia (28%), Qatar (22%) and the United States (10%).

Australia has long been the biggest source of LNG for countries like Japan, China and Taiwan and a major supplier to South Korea. The US LNG industry continues to expand rapidly, with growing supply roles across Japan, South Korea, Taiwan, Thailand and India.

Conclusion

While gas and LNG have emissions profiles that require monitoring and management, it’s clear that their use will have a positive impact on decarbonisation in Asia. Switching out coal-fired power for gas-fired power can help nations in Asia achieve meaningful emissions reductions and advance the energy transition.

Within that equation, there is a strong need for the global gas industry to continue to work to reduce lifecycle emissions through the LNG value chain. The current focus on improving methane management and decarbonising operations reflects the industry’s commitment to doing this.