Global warming has long reached the boiling point that resolute and immediate action is needed. As the primary contributor to the issue, reducing greenhouse gas (GHG) has been the main focus in alleviating climate change. Methane, a more potent GHG than carbon dioxide, has been found to also have a substantial role in the climate crisis, particularly emissions in the energy sector. Here, we examine the environmental impacts brought by methane emissions, how leakage and venting from the energy sector is a major source of it, as well as potential solutions.
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How Does Methane Emissions Affect Global Warming?
Methane (CH4) is a major contributor to the total GHG emissions, second only to carbon dioxide (CO2). Though CO2 is more commonly and widely discussed, concerns about methane emission should not be ignored.
Global greenhouse gas emissions by gas (1990-2010). Image: US Environmental Protection Agency.
Global methane emissions have been on the rise, with an annual increase of 17 parts per billion in atmospheric methane in 2021, the largest annual increase recorded since 1983. Atmospheric methane levels are also shown to be 162% higher than pre-industrial levels, alarming the scientific community.
Globally-averaged, monthly mean atmospheric methane abundance. Graph: NOAA.
Besides its worryingly growing emission, methane is found to be a significant and impactful GHG; it is 84 times more potent in trapping the heat than carbon dioxide over a two-decade period. The gas also possesses a global warming potential 25 times more than that of carbon dioxide.
Though one particular feature of methane that should be noted: its shorter life span. Methane will be broken down in less than a decade, which is a much faster rate compared with CO2 but stays in the atmosphere for more than a century. Lowering methane emissions could therefore yield a rapid decline in the rate of global warming.
Professor Drew Shindell, physicist and climate specialist at Duke University’s Nicholas School of the Environment, agrees that targeting methane makes for a quick and short-term solution to climate change. “We’re seeing so many aspects of climate change manifest themselves in the real world faster than our projections,” he noted. “We don’t have a lot we can do about that, other than this powerful lever on near-term climate of reducing methane. We should do this for the wellbeing of everybody on the planet over the next 20 to 30 years.”
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Methane and the Energy Sector
Though the agricultural sector is the major culprit of the human-caused or anthropogenic methane emissions, the energy sector also contributes a large proportion of emissions, closely following the farming industry. During the different production stages of energy generation, emission of methane can occur.
Methane emissions can be classified into unintentional and intentional emissions.
Methane leakage refers to the unintentional and involuntary release of gas, while venting refers to the intentional and controlled release of it. Leakage occurs most likely in aged equipment and facilities which lack regular and proper maintenance, whereas venting is done to dispose gases that lack value. Natural gas flaring is another intentional release of methane, defined as the controlled combustion of natural gas for operational, safety, or economic reasons.
Since fossil fuels, which include coal, oil and natural gas, remain to be the main sources for the energy sector, their production is closely tied to methane leakage and emissions.
Sources of methane emissions. Image: IEA.
1. Coal
Methane is produced during coalification, the geological formation of coal. Extraction, crushing and other coal mining activities release methane that is trapped around and within the rock strata. The majority of methane emissions from coal could be found in active underground mines, underground or closed mines, as well as surface mines. Methane is released through the degasification systems and ventilation systems in the active underground mines. Venting of methane, due to safety reasons, is released from diffuse vents, ventilation pipes, boreholes, or fissures in the ground from the abandoned or close mines.
US coal mine methane sources (2019). Image: US Environmental Protection Agency.
2. Oil and Natural Gas
Similar to coal, a large number of methane deposits are produced during the geological formation of oil. The GHG are released during the extraction and drilling of oil, as well as during refinement, transportation and storage. Incomplete and inefficient combustion of oil, as with other fossil fuels, will also unintentionally emit methane.
For natural gas, compressors, valves, pumps, flanges, gauges and pipe connectors are some of the many individual components that are easily subject to methane leaks. Methane can also be intentionally released after hydraulic fracturing, vented from storage tanks, dehydrators, as well as depressurising equipment. Venting from the production of natural gas, as well as oil, is often due to system upset conditions or pressure release emergencies.
Methane is released along the supply chain of both oil and natural gas. Production, processing, transmission, as well as distribution are some of the supply stages in which unintentional leakage and venting of methane could be found.
During the production stage, methane is leaked from pneumatic controllers, gathering and boosting stations, chemical injection pumps etc. For the processing stage, gas engines, reciprocating compressors, as well as centrifugal compressors are some of the contributors to the methane emission. For the transmission stage, pipelines, station venting, and station fugitives are other emitters that should be played attention to. Lastly, for the distribution stage, methane leakage could be found at industrial meters, residential meters, unprotected steel etc.
Natural gas being flared due to maintenance issues. Photo: US Department of Energy.
Methane Leakage Solutions
It is estimated that with proper and adequate abatement options, 75% of total oil and gas methane emissions could be avoided, 40% of which could have been prevented with zero-net-cost measures. The solution to methane leakage can therefore be cost-effective, and more measures should be taken in order to alleviate the issue.
1. Environmental Technology and Innovation
Together with detecting and monitoring equipment such as satellite and infrared cameras, software systems are developed to track the location where methane leakage occurs. Plane-mounted sensors and satellites allow high-precision measurements of methane emissions, and assist with the monitoring of methane vents. Installing systems also could be designed to capture the vented and leaked methane, reusing the leakages as fuel and supplemental power source for the facility.
Besides detecting and monitoring, replacing aged equipment with advanced one is key to lowering methane emissions. “Zero-bleed” electric motors could replace gas-driven pneumatic devices, which constantly release methane. Electric motors can also be used to replace diesel or gas engines during drilling. Instrument air systems are another option.
While technological advancement could tackle some of the methane leakage problems, research on environmental technology and innovation is also needed. Natural Resources Canada, for instance, is actively developing and advancing its green technology, and initiating an aerial and satellite-based methane detection network. Advanced Methane Detection, Analytics and Mitigation Project researches the use of remote sensing sensors, software, solar electric system solutions sensor and related technologies to address methane emission in the energy sector.
2. Action from International Organisations
International organisations such as the United Nations and the European Union can play an important role in regulating and monitoring environmental issues, encouraging collective action and exchange of information among countries.
The Oil and Gas Methane Partnership (OGMP) 2.0 framework, initiated by the EU, has proposed certain measurements for the regulation of methane emission. For the oil and gas sector, venting is only allowed for safety reasons under unavoidable circumstances. Flaring is prohibited in incomplete combustion to reduce emissions from inefficient combustion. For coal, venting and flaring from drainage stations are being proposed to be banned by 2025, and from ventilation shafts by 2027. Member states are also required to set up plans for abandoned coal mines and inactive oil and fossil gas wells.
Similarly, the International Methane Emissions Observatory (IMEO) set up by the UN Environment Programme (UNEP) aims to generate a public dataset of empirically verified, near-real-time methane emissions data. Data is sourced from companies, satellites, scientific studies and national inventories, creating peer-reviewed data streams using advanced data science methodologies. With this disclosure, accurate and credible data sources for research are provided, and increases public transparency regarding companies’ emissions of GHG.
3. Role of Government
Governments play a large part in environmental protection, with its ability to legalise and standardise certain regulations. Clear standards and requirements are needed to create acceptable levels of methane emission, as well as the technological level needed for the equipment. Regular maintenance and inspection of facilities should be required to detect any leakage and venting of methane. Legalisation of these regulations can therefore penalise (via taxes or fines) companies that fail to comply and deter them from repeating offences.
Subsidy, loans or other financial incentives should be offered to encourage technological research for environmental innovation as well.
The methane emission trend will take some time to be flattened, but substantial and active steps are critical from different sectors and stakeholders. Regular maintenance and replacement of facilities by the energy companies are a must, and an increase in their cost in regular maintenance and replacement of worn-out equipment is likely. Adopting more advanced green technology will also increase firms’ expenses. Fossil fuel companies should be asked to bear more corporate social responsibility while governments should provide more assistance and subsidise research on green technology. Combined, methane emissions could certainly face a diminishing trend soon.
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Featured image by: Ken Doerr/Flickr (CC BY 2.0)
