Methane – made up of one atom of carbon and four atoms of hydrogen (CH4) – is powerful stuff.
On positive side, power generated from natural gas, of which methane is the primary component, offers far lower CO2 emissions compared to burning coal – making gas an important tool in the ongoing transition towards lower-carbon energy.
On the down side, the rise in production of natural gas increases the odds of additional methane being released into the atmosphere. In the short term, atmospheric methane contributes more to climate change than an equal measure of carbon dioxide. By way of comparison, the International Energy Agency (IEA) explains that the effect of just 1 tonne of methane is “…equivalent to 28 to 36 tonnes of CO2 if looking at its impact over 100 years.”
Identifying the source
According to the IEA, “The concentration of methane in the atmosphere is currently around two-and-half times greater than pre-industrial levels and is increasing steadily.” In part, methane occurs naturally, and some 30% of the methane released into the atmosphere annually comes from wetlands, as well as another 9% from natural sources such as fresh waters, geologic seepage, wild animals, termites, wildfires, permafrost and vegetation.
The remaining 61% is the result of human activity, with the largest percentage (24%) from agriculture. Methane as a by-product of energy activities includes 20% as a result of oil and gas production and use, with another 6% from biofuels and biomass burning (roughly 3% for each). Methane escaping from waste accounts for 11%.
Awareness is perhaps one of the most important tools that we can use to reduce methane emissions, and the IEA’s recently launched “Methane tracker” includes a specific focus on proactive steps the oil and gas industry can take to mitigate emissions:
“Oil and gas producers that can demonstrate that they are taking strong action to reduce methane emissions can credibly argue that their resources should be preferred over higher-emission options. It is crucial for the oil and gas industry to be proactive in limiting, in all ways possible, the environmental impact of oil and gas supply, and for policy makers to recognise this is a pivotal element of global energy transitions.”
Taking awareness one step further, the US-based Environmental Defence Fund (EDF) has begun a programme to measure and evaluate methane emissions in real-time.
MethaneSAT LLC, an affiliate of the EDF – is scheduled to launch a methane-detecting satellite in 2021. The MethaneSAT programme’s goal is to identify where methane emissions are coming from and how large they are. By charting emissions over time, the project will be able to identify areas for potential reductions as well as track whether progress has been made with methane reduction efforts.
In addition to tracking and working to reduce methane emissions from oil and gas activities, capturing methane from agricultural sources to produce renewable natural gas (RNG) will help to lower emissions.
This past summer in California, Southern California Gas Co. (SoCalGas) and Calgren Dairy Fuels announced the opening of a dairy renewable natural gas facility that harnesses the methane emissions from dairy digesters and converts it into RNG for use in homes and businesses – for cooking and to fuel trucks and busses.
From tracking to reducing
The IEA’s Methane tracker points to abatement as key. Some 75% of oil- and gas-related methane emissions could be avoided by using existing technology. This would be a win-win, avoiding waste, which leads to an improvement in energy efficiency, and lowering emissions – something we can all live with.