The below article talks about methane, the properties of methane, the sources, the environmental impacts, the uses of methane, along with some frequently asked questions about methane and its impact on the world around us.
Why is methane known as a greenhouse gas?
Gases that have the capability to trap and retain heat within the Earth’s atmosphere are called greenhouse gases, and methane is a greensource gas that has a warming potential that is 80 times higher than carbon dioxide. There are various sources that emit methane including activities in the extractive industry, agricultural activities, from livestock, landuse patterns, decay of organic waste, etc. In 2020, estimated emissions of methane amounts to 76,424 kt (IEA, 2021).
Methane, a gas lighter than air burns readily to form carbon dioxide and water vapour. The boiling point of the chemical is -162 ℃ and melting point is -182.5 ℃. While gas is stable in general, in specific concentrations between 5% to 14%, it can be explosive in nature. Therefore, methane has been used for years to instigate several explosions, especially those in mines or quarries. In 2019, methane contributed to 10% of the US ‘s total greenhouse gas emissions, and could be directly attributed to anthropological activities. Sources of methane are varying and can be released in different concentrations depending on the activity, it is also to be observed that methan can be emitted from natural sources such as natural wetlands.
While methane has a shorter life span than carbon dioxide in the atmosphere, it is far more capable in retaining heat within the planet and increasing global temperatures. It is estimated that globally, 50% to 65% of methane emissions are from human activities, some of these sources have been mentioned below:
- Environmental sources of methane include wetlands, where anaerobic decomposition of organic matter under watter forms marsh gas or swamp gas, which is mostly methane.
- Other environmental sources include volcanoes, termites as a result of their digestive processes, methane deposits, ocean floor vents, wildfires, etc.
- Depending on the source of natural gas, methane concentrations can vary from 50% to 90%, combustion of natural gas causes massive methane emissions.
- Combustion and production of other fossil fuels such as coal and oil, gives out large quantities of methane into the atmosphere. Activities that produce large concentrations of methane in relation to fossil fuel activities include the extraction and processing of natural gas, distillation of bituminous coals to form coal gas or coke-oven gas, etc.
- Agriculture and agricultural practices are a large contributor to methane emissions globally, especially since livestock produce methane as part of their digestive processes, and storage of organic animal manure, causes large methane emissions. Since anthropological activities in relation to mass production for meat and diary and other animal-sourced products create a platform for large-scale livestock farming, these emissions are attributed towards human activities.
- Methane can be released during several waste treatment processes as well as from landfills. In the US, landfills are the third largest source of methane. The gas has been found to be emanated from domestic or industrial wastewater treatment activities, as well as from composting, and anaerobic digestion.
Below is a chart depicting the sources of methane in million tonnes, provided by IEA (IEA, 2021)
|Wetlands (Natural)||194 Mt|
|Agriculture (Anthropogenic)||145 Mt|
|Energy (Oil)||36 Mt|
|Energy (Gas)||41 Mt|
|Energy (Coal)||42 Mt|
|Energy (Bioenergy)||10 Mt|
|Anthropogenic Waste||68 Mt|
|Other (Natural Sources)||39 Mt|
|Biomass Burning||16 Mt|
Uses of Methane
Methane has been used globally for several purposes, and usage of fossil fuels has directly and indirectly contributed towards methane emissions. Some of the common uses of methane are the following:
- Methane being a hydrocarbon and lighter than air, it is capable of producing more energy per unit weight in comparison to other usual fuel sources such as coal or oil. Methane does not leave any form of soot residue or have any smell, therefore it is preferred over other fuel sources, especially for cooking.
- Methane is used for heating and cooling systems in residential areas. It can also be used in other household activities including being used in the form of a natural gas firestarter for fireplaces, natural gas dryers for clothes, etc.
- Methane can be used to generate electricity in different scales depending on needs such as for residential purposes, industrial activities, offices, etc. through a process called distributed generation, using microturbines and natural gas fuel cells.
- Methane is usually used in the formation of several other chemical compounds such as methanol, an important element for alcohol. Methane is also a crucial element to creating hydrogen that is used in several industries. Another common chemical made with methane is the hydrochloric acid and trichloromethane, a.k.a. Chloroform which is used as a solvent and as an anaesthetic.
- Methane gas is used in many industries to power engines and turbines. Industries such as paper or pulp industry, food processing industries, petroleum refineries, glass industries, etc. use methane to power their equipment, specifically, it uses the heat that is generated by the gas to power the equipment.
- Methane helps several industries in processes such as drying, dehumidifying, melting, sanitizing products, lighting within these industries, etc.
- Burning methane incompletely leads to large carbon depositis called carbon black, this is usually used to strengthen rubber for vehicle tires. This carbon form is also used to make printing inks and paints.
- Methane is an important ingredient for fertilisers, where on adding hydrogen, methane is able to produce ammonia, which is crucial for agricultural fertilizers.
- If methane is effectively used, it leaves no carbon depositis or soot due to which it is a preferred ingredient in making rocket fuels. Other fuel sources could make the rocket combustion chamber faulty.
Methane is accelerating climate change
IEA estimates that the concentrations of methane currently is 2.5 times more than pre-industrial levels, and is ever-increasing. This increase will have drastic impacts on climate change, and will accelerate any environmental disaster that is faced by citizens around the world. Methane will have important implications on the environment, although it exists for a shorter term in comparison to other greenhouse gases. It needs to be noted that methane has implications on holistic health of humans and other ecosystems as well, as it is a major component towards air pollution.
Methane’s capability to store and retain large amounts of energy, in the short time that they do exist in the environment, will rapidly accelerate global temperatures and increase the impacts of global warming, methane only lasts for 12 years in comparison to the centuries it takes carbon dioxide, however, its potential for heat retaining causes far more damage. IPCC reports that methane has a global warming potential between 84 to 87 in a 20 year period, and 28 to 36 when considering its impact over 100 years. This essentially means that one tonne of methane causes the same damage as 28 to 36 tonnes of carbon dioxide in a 100 years.
Frequently Asked Questions (FAQs): What do I need to know about methane?
Why focus on methane mitigation in comparison to other greenhouse gases?
For many years, methane was overlooked because it contributed to lesser volumes of greenhouse gases, in comparison to carbon dioxide. However, on recognising that methane, though lower in volume, has a much higher capacity to create damage, it has been brought to the spotlight and needs to be immediately mitigated to reduce the impacts on the planet and different ecosystems. Methane emissions today has been found to directly cause approximately 25% of the world’s increasing global temperatures, and the concentrations and volumes of methane is increasing than before ever since the industrial revolution, due to the massive usage of fossil fuels.
Addressing methane emissions would be the first step for policy-makers, program designers, and enforcers in slowing down climate change and its impacts. Addressing methane immediately will also help actors across the world to build resilient strategies to wane off of the usage of fossil fuels, and create alternative fuel sources that are much more efficient, effective, and sustainable.
Can existing equipment or devices used be upgraded or modified to reduce methane emissions from different kinds of activities?
Yes, there are many changes that can be made in order to ensure that the equipment or devices used in industrial or manufacturing processes give out lesser methane emissions. Changes must be made by providing companies with incentives to do so, so that the larger sources of methane can be reduced, thus slowing sown global warming, and some of the changes that could be made include the following:
- Replacing pumps controllers in oil and gas operations with instrument air systems, which can pressurise ambient air as a power source, to produce the same function as natural gas in their industrial activities.
- Replacing pressurized natural gas pumps, that is used as a power source with pumps that can be alternatively fuelled such as through solar power, generators, attached to the main gride, etc. Replacing Kimray/ pneumatic or chemical injection pumps with electric or solar powered pumps.
- Gas driven industrial devices often release small amounts of gas, and these could be replaced with devices that state that there would be no bleeding of gases, and these devices would be electrically powered instead of being powered by diesel/ gas engine, pressurized natural gas, etc.
- Oil and natural gas supply chains use two kinds of compressors to move the product across the supply chain: reciprocating compressor or centrifugal compressor. IEA has specifically described how updating and changing these devices could drastically improve methane emissions, and they can be found here.
- It is important for industries and other larger stakeholders to realise that at a point, all their devices will need to be changed in order to ensure maximum efficiency and effectivity, and to ensure lower bleeding of gas from these devices, and each of their devices would be categorized based on the quantities of gas they bleed, and eventually these devices would need to be replaced with zero bleed devices, to ensure that overall industrial activities are addressed when it comes to being sustainable and reducing global emissions.
Other FAQs about Air Quality that you may be interested in.
Britannica. (2021, October 29). Methane: Chemical Compound. Viewed on 12-24-2021. https://www.britannica.com/science/methane
Conserve Energy Future. (n.d.). What is Methane Gas? Viewed on 12-24-2021. https://www.conserve-energy-future.com/sources-uses-effects-methane-gas.php
Environmental Defense Fund (EDF). (n.d.). Methane: A crucial opportunity in the climate fight. Viewed on 12-24-2021. https://www.edf.org/climate/methane-crucial-opportunity-climate-fight
IEA. (2021). Methane Abatement Options. Methane Tracker 2020. Viewed on 12-24-2021. https://www.iea.org/reports/methane-tracker-2020/methane-abatement-options#abstract
IEA. (2021). Methane from Oil & Gas. Methane Tracker 2020. Viewed on 12-24-2021. https://www.iea.org/reports/methane-tracker-2020/methane-from-oil-gas
IEA. (2021). Methane and Climate Change. Viewed on 12-24-2021. https://www.iea.org/reports/methane-tracker-2021/methane-and-climate-change
IEA. (2021, October 07). Methane Tracker Database. IEA, Paris. Viewed on 12-24-2021. https://www.iea.org/articles/methane-tracker-database
US Environmental Protection Agency (US EPA). (n.d.). Overview of Greenhouse Gases. Viewed on 12-24-2021. https://www.epa.gov/ghgemissions/overview-greenhouse-gases