Why natural gas is dirty and dangerous

Natural gas is not cleaner than other fossil fuels. In fact, investing in gas as an energy source in South Africa is unnecessary, economically risky, and comes with a number of public health and climate change threats.

Like coal and oil, natural gas (sometimes called fossil gas) is a fossil fuel that can be burned for energy. Natural gas formed in the earth’s crust millions of years ago and is made up mostly of methane, along with smaller amounts of butane, ethane and propane gases.

The fossil fuel industry tries to associate the “natural” in natural gas with clean energy, but this is deceiving. There is nothing clean about gas. While it is produced from decomposing plant and animal matter, it is still a dirty fossil fuel.

As gas production and the trade in liquefied natural gas (LNG) has grown, so too has scientific research showing the negative effects of gas production and use on human health and the planet.

Upstream industry: extraction

• Polluting emissions impact air quality and contribute to climate change. Gas production degrades local and regional air quality, and creates health risks for those living nearby. The main polluting emissions from natural gas systems include methane, nitrogen oxides (NOx), volatile organic compounds (VOCs) and other hazardous air pollutants such as benzene, hydrogen sulphide, formaldehyde, and hexane.
• Human health suffers. Research shows that these pollutants have significant health consequences including adverse birth outcomes, premature mortality in elderly individuals and exposure of workers to carcinogenic and radioactive material.
• Water pollution and water scarcity increases. Drilling for oil and gas and hydraulic fracturing can contaminate ground and surface water via several pathways, including failures in gas well seals and poor management of the hazardous waste that results from oil and gas production. These liquid and solid wastes, which are produced by in large quantities in oil and gas operations, contain toxic chemicals used in the drilling process and hazardous materials brought out of the earth, including endocrine disruptors and carcinogens. The large quantities of water needed for gas extraction at each gas well can also deplete local water supplies, straining water resources in water-scarce regions. This impacts farming, existing land uses, and livelihoods of communities in areas surrounding production.
• Land degradation, marine degradation and habitat loss occur. Construction of wells and associated infrastructure destroys and fragments wildlife habitats and results in vegetation and potentially biodiversity loss. Gas operations in the shrublands of South Africa, a region primarily composed of dry shrubland, would likely degrade this ecosystem and harm local wildlife. A U.S. study found that 80 years after closure of oil and gas wells, vegetation within the semi-arid brush land around well sites in the U.S. state of Wyoming had not recovered. These habitat losses are also particularly relevant for offshore gas production. Land degradation caused by gas extraction harms the healthy ecosystems that our planet needs in order to withstand the effects of climate change.

Midstream industry: processing and transportation

• Harmful air pollutants are released. A 2022 study found that short-term exposure to particulate matter 2.512 (PM2.5) derived from production, processing, and transportation of natural gas as well as sulphur dioxide (SO2) emissions from gas flaring were linked to respiratory hospitalisations among children in Bintulu, Malaysia. LNG infrastructure such as gas processing and liquefaction facilities, as well as ship terminals, also harm local communities via chronic exposures to air pollutants, and acute risks. These risks include vapor cloud explosions like those at the Skikda LNG plant in Algeria, where a leak of refrigerants led to an explosion that killed 27 people and injured many more.
• Gas leaks and explosions are more likely to occur. Gas pipelines themselves are prone to corrosion and breaks, which can result in gas leakage, explosions, and fires.
• Greenhouse gases are emitted. When gas is transported as LNG, the liquefaction, transport, and regasification of this gas increases lifecycle greenhouse gas emissions beyond those from transporting gas by pipeline, assuming no major leaks in the pipeline.

Downstream industry: when gas is used

• Burning gas for energy causes large quantities of harmful emissions and hazardous waste. In South Africa the current and proposed future uses of gas include industrial heating, gas-to-liquid plants, and gas-to-power plants. Burning gas at power plants emits nitrogen oxide (NOx) and carbon dioxide (CO2), as well as volatile organic compounds, methane and hazardous air pollutants like formaldehyde as a result of inevitable incomplete combustion. Methane traps over 80 times as much heat as carbon dioxide when measured over a 20-year period, exacerbating the climate change impact of greenhouse gas emissions.
• Gas-to-liquid plants, which Sasol pioneered to convert gas into liquid fuels, emit greenhouse gases, volatile organic compounds and other hazardous air pollutants, and generate large quantities of waste like waste oils, sludge, hydraulic fluids, waste chemicals, contaminated wax wastes, and spent catalysts.
• Health is impacted. At low levels the NOx from gas-to-power plants results in respiratory symptoms such as coughing, shortness of breath, and throat irritation, and at high levels may cause more severe symptoms, airway damage, and even death. NOx also creates additional health and environmental impacts when it reacts with other chemicals in the atmosphere to form acid rain, particulate matter, and ozone.

Hazardous to human health and the planet

At the local and regional level, natural gas development is associated with water overuse and contamination, hazardous air pollution, light and noise pollution, and acute risks like fires and explosions. These developments create public health and environmental risks and generate harmful emissions during each stage of its life cycle.

Major contributor to climate change

When natural gas is burned for energy, it releases carbon dioxide into the atmosphere. More importantly, the extraction, processing, transport and use of natural gas cause significant amounts of methane to be released into the atmosphere too. According to the United Nations, methane is a 84-86 times more potent greenhouse gas than carbon dioxide over a 20-year period, and 28-34 times more potent over 100-year period. More research is also showing that methane often leaks during the production, transport and use of natural gas. Therefore, its contribution to climate change is significantly unaccounted for.

The consideration of the full lifecycle GHG emissions and the full footprint of the sector is essential in considering whether it is the best option for investment in South Africa.

No such thing as a ‘clean fossil fuel’

A holistic and cumulative lifecycle impact assessment approach must be employed when a gas project is proposed. This would be in line with national environmental legislation and the Best Practice Principles for impact assessments, as published by the International Association of Impact Assessment, and it would reflect the total GHG emissions resulting from the use of gas.

Understanding the full impact of gas developments would counter the misconception that gas can be used as a strategy to reduce emissions and combat climate change and would help to bust the myth that ‘gas is the cleanest fossil fuel.’

With thanks to Staff Scientist Lauren Withey and Jessica Citrola, Climate Mitigation Science and Policy Fellow at Earthjustice, for the research and compilation of facts that led to this factsheet.

Source: Centre for Environmental Rights (CER)