What is Liquefied Natural Gas?

ACE Staff Writer

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November 17, 2023

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Liquefied natural gas (LNG) has been touted as a cleaner alternative to traditional fossil fuels like coal and oil. It’s often seen as a bridge fuel, a way to transition to a lower-carbon energy system while still meeting our current energy demands. But LNG’s production and use still have significant environmental and public health impacts that need to be taken into account.

What is Liquefied Natural Gas?

Natural gas is a fossil fuel that is primarily composed of toxic methane gas, with smaller amounts of other hydrocarbons like ethane, propane, and butane. It’s found deep underground and is typically extracted using drilling techniques like hydraulic fracturing, or “fracking”.

To make natural gas easier to transport over long distances, it can be cooled to a temperature of -260°F, at which point it becomes a liquid. This liquid form of natural gas is called liquefied natural gas, or LNG.

Liquefied Natural Gas is typically stored in large tanks and transported in specialized tankers. When it reaches its destination, it can be converted back into a gas and used for a variety of purposes, including heating homes and buildings, generating electricity, and fueling vehicles.

LNG Production and Transport

The production and transport of LNG involve several steps, each of which has its own environmental and public health impacts.

Extraction

The first step in producing LNG is to extract natural gas from underground reservoirs. This is typically done using hydraulic fracturing, which involves injecting large amounts of water, sand, and chemicals into the ground to release the natural gas.

While fracking has made it possible to access previously untapped sources of natural gas, it has also raised concerns about its environmental impacts. Fracking can contaminate groundwater and surface water with chemicals and methane, a potent greenhouse gas that can escape during the extraction process.

In addition to the environmental impacts of fracking, the process has significant public health impacts. People who live near fracking sites have reported health problems like respiratory issues, headaches, and nausea, which scientists believe is linked to exposure to air and water pollution from fracking operations.

Processing

Once natural gas has been extracted, it needs to be processed to remove impurities like water, carbon dioxide, and other gases. This process can involve compressing the gas to increase its density and make it easier to transport.

The processing of natural gas can have environmental impacts as well. For example, it requires large amounts of energy, which can contribute to greenhouse gas emissions. In addition, the processing can generate wastewater and other waste products that need to be disposed of safely.

Transport

After processing, natural gas is typically transported through pipelines to storage facilities or processing plants. However, in order to transport natural gas over long distances, it needs to be converted into LNG. As the Natural Resources Defense Council states, “The energy required to chill, ship, and regasify the fossil fuel makes it far more carbon-intensive and increases the potential for leakage of dangerous methane.”

The transport of LNG can have significant environmental impacts. LNG tankers emit greenhouse gases and air pollutants like sulfur dioxide and nitrogen oxides, and there is always a risk of accidents or spills that can damage marine ecosystems and harm human health.

Storage

LNG is typically stored in large tanks that are designed to keep the gas at a very low temperature. These tanks are often located near ports or other transportation hubs.

The storage of LNG can have environmental impacts. For example, if LNG tanks are not properly maintained, there is a risk of leaks or spills that can harm the environment and public health.

Impacts on People

The production and transport of LNG can have significant impacts on the health and well-being of people who live near fracking sites, processing plants, and transport routes.

Air Pollution

The processing and transport of natural gas and LNG can release air pollutants like volatile organic compounds (VOCs), nitrogen oxides (NOx), sulfur dioxide (SO2), carbon monoxide (CO) and particulate matter (PM), which contribute to respiratory problems, heart disease, and other human health issues. These pollutants can be especially harmful for vulnerable populations like children, the elderly, and people with pre-existing health conditions.

In addition, the production and transport of natural gas can release methane, a potent greenhouse gas that contributes to climate change. Methane leaks occur at various stages of the natural gas production and transport process, including during fracking, processing, and transport. According to the Environmental Defense Fund, methane leaks from natural gas systems are the second-largest source of methane emissions in the United States, after agriculture.

Water Pollution

The production of natural gas through fracking can contaminate groundwater and surface water with chemicals and other pollutants. Fracking involves injecting large amounts of water, sand, and chemicals into the ground to release natural gas, and these chemicals often find their way into nearby water sources. In addition, the wastewater produced during fracking can contain high levels of salt, chemicals, and heavy metals, which can also contaminate water sources if not properly disposed of.

In some cases, the contamination of water sources from fracking has led to public health emergencies. In 2014, a chemical spill in West Virginia contaminated the local water supply, leaving 300,000 people without access to clean water for several days.

Plant Explosions

LNG plant explosions pose a significant danger due to the unique properties of LNG. LNG is stored at extremely low temperatures, making it highly volatile, and in the event of a leak or breach, it can rapidly vaporize and form a flammable gas cloud. If ignited, these clouds can result in catastrophic explosions with the potential for severe damage to infrastructure, injuries, and loss of life, like the tragic explosion at the Freeport LNG plant. The intense heat generated during an LNG explosion can also have far-reaching environmental consequences, as it can ignite nearby structures, leading to fires and the release of toxic gases. Proper safety measures, robust emergency response plans, and strict regulations are crucial in mitigating the risks associated with LNG plant operations.

Impacts on the Environment & Climate

In addition to the impacts on human health, the production and transport of LNG can have significant environmental impacts. As we discussed, liquefied natural gas is primarily composed of methane, a potent greenhouse gas with a much higher global warming potential than carbon dioxide (CO2) over shorter time frames. When burned for energy, natural gas produces fewer CO2 emissions per unit of energy compared to coal or oil. This characteristic has led many to consider natural gas, and by extension, LNG, as a bridge fuel towards a lower-carbon energy future. However, the overall climate impact of LNG extends beyond combustion emissions.

Greenhouse Gas Emissions

While natural gas is often touted as a cleaner alternative to other fossil fuels, the production and transport of natural gas and LNG can still release significant amounts of greenhouse gases. In addition to methane leaks, the production and transport of natural gas and LNG requires large amounts of energy, which can come from fossil fuel sources like coal and oil. This energy use contributes to greenhouse gas emissions and climate change.

In addition, the process of liquefying natural gas requires large amounts of energy, which also contributes to greenhouse gas emissions. According to the International Energy Agency, the production and transport of LNG can result in greenhouse gas emissions that are up to 30% higher than those from conventional natural gas.

Habitat Destruction

The production and transport of natural gas and LNG can also have significant impacts on wildlife and natural habitats. For example, fracking can require large amounts of land to be cleared and developed, which can lead to the destruction of natural habitats and the displacement of wildlife.

In addition, LNG terminals and other infrastructure have significant impacts on coastal ecosystems and wildlife. For example, the construction of LNG terminals can disrupt seafloor habitats and marine ecosystems, and LNG tankers can collide with marine mammals like whales and dolphins.

Methane Emissions

The production and transportation of natural gas, including LNG, are associated with methane leakage. Methane can escape from wellheads, pipelines, and storage facilities, which significantly amplifies its climate impact. Over a 20-year period, methane is estimated to be over 80 times more potent as a greenhouse gas than CO2. Therefore, substantial methane emissions can offset the benefits of reduced CO2 emissions during combustion.

Additionally, identifying and reducing fugitive methane emissions are critical to minimizing LNG’s impact on climate change. Fugitive methane emissions are the unintentional release of methane into the atmosphere. These emissions occur primarily during the production, processing, and transportation of fossil fuels, particularly in the oil and gas industry. Investments in technology for detecting and mitigating emissions are ongoing, but comprehensive monitoring and control are essential and not currently in place.

Life-Cycle Assessment

To evaluate the climate impact of LNG, scientists use a life-cycle assessment (LCA) that considers emissions across the entire supply chain, from extraction to end-use. This comprehensive approach accounts for methane emissions, which can be substantial in some cases. Depending on the extent of these emissions, the overall climate impact of LNG can vary considerably.

Fugitive Methane

Identifying and reducing fugitive methane emissions are critical to minimizing LNG’s impact on climate change. Improved infrastructure, equipment, and regulations can help prevent leaks, making natural gas and LNG more environmentally friendly. Investments in technology for detecting and mitigating emissions are ongoing, but comprehensive monitoring and control are essential.

Comparative Climate Impact

Over a short time frame (e.g., 20 years), the warming potential of methane from natural gas and LNG is high. This means that if methane emissions are not adequately controlled, LNG could have a more substantial climate impact than coal. However, over longer periods (e.g., 100 years), the global warming potential of methane diminishes compared to CO2, which may make natural gas and LNG a more attractive option.

LNG as a “Transition Fuel”

The classification of LNG as a “transition fuel” by oil and gas lobbyists and industry groups is a contentious point that deserves critical examination. While proponents argue that LNG can play a role in reducing CO2 emissions compared to coal and oil, especially in regions heavily reliant on coal, it’s essential to consider its actual impact on transitioning to clean, renewable energy sources. The long-term role of LNG in a sustainable energy future depends on addressing methane emissions and eventually phasing out natural gas in favor of even cleaner alternatives.

Firstly, the labeling of LNG as a “transition fuel” can create a sense of complacency. It might lead to the delay or weakening of efforts to transition to cleaner alternatives, as the industry’s focus remains on extracting, processing, and exporting natural gas. This diverts investments and resources from the development and scaling of truly sustainable, renewable energy technologies.

Secondly, the economics of LNG infrastructure can lock in fossil fuel dependency for decades. Investments in LNG facilities, including pipelines and export terminals, are massive and long-term. These investments incentivize continued natural gas production and consumption, making it difficult to shift resources and priorities to renewables.

Furthermore, the leakage of methane emissions along the natural gas supply chain poses a significant challenge. Unmitigated methane emissions can outweigh the short-term reduction in CO2 emissions, thus undermining the environmental benefits of switching from coal or oil.


Liquefied natural gas is often seen as a cleaner alternative to other fossil fuels, but its production and use have significant environmental and public health impacts.

Want to take action and stop the expansion of liquefied natural gas? Click below and tell the Biden Administration and the Department of Energy to halt all new LNG permit approvals until they look at the impact these facilities will have on our communities, the climate, and US consumers.

ACE Staff Writer

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