The fact that methane emissions from the oil and gas sector are said to be vastly underreported clearly shows that natural gas is not “very clean”
Natural gas is a fuel that has been promoted as a viable solution for countries looking to transition away from coal and oil. In the pursuit towards renewables and electrification, natural gas has been given the tag of a ‘bridge fuel’. Natural gas is claimed to be a cleaner energy source than other fossil fuels, with 50 per cent less CO2 emission into the atmosphere.
But what is the real truth behind these tall claims?
The plans of the Intergovernmental Panel on Climate Change to phase out coal for the 1.5°C pathway places a heavy burden on coal-dependent Global South countries. The developed nations are using this urgency to conveniently forget their role in being historical polluters and are now asking the Global South to use “transitional fuels” for energy security. But let’s get some facts clear about natural gas: Firstly, from a climate standpoint, coal and gas are compared by assessing their life cycle greenhouse gas (GHG) emissions.
Read Is natural gas actually cleaner than coal? Growing evidence says maybe not
A “lifecycle assessment” evaluates all the emissions throughout the coal and gas supply chains from extraction, processing, and transportation to end use. Comparisons based only on end-use combustion might paint an incomplete picture of the total GHG emissions. Data shows that a given coal-fired power plant in Europe emits GHG of 970 tonnes of carbon dioxide equivalent (CO2e) per gigawatt-hour of electricity over its lifecycle. In comparison, a given oil-fired power plant emits 720 tonnes and a given gas-fired power plant emits 440 tonnes of CO2e per gigawatt-hour of electricity, over their respective lifecycles. However, the problem with this assessment is that it omits the importance of considering methane emissions alongside CO2 emissions when comparing coal to gas. The primary component of natural gas is methane, comprising 70-90 per cent of its composition. Methane is the second-most abundant GHG after CO2 and has a much stronger planetary warming effect.
Methane has 28 times more global warming potential (GWP) than that of CO2 over 100 years. Methane also traps over 82.5 times more heat than CO2 over 20 years. So, it is evident that methane has a strong near-term warming effect, unlike the long-term potency of CO2. But traditional climate models measuring the effects of methane over 100 years could end up overlooking its immediate heat-trapping potential, possibly skewing policy conclusions of natural gas versus coal emissions.
Secondly, The Clean Air Task Force (CATF), analysis of LNG shipments exported from the US to Vietnam and coal exported from Australia to Vietnam shows that upon usage of these fuels in the country, a gas-fired power plant emits 58 per cent less CO2 from its stack than a coal-fired power plant. Again, they are not looking at the full picture.
According to researchers, they are not accounting for CO2 emissions from gas liquefaction during transport. The GHG footprint of LNG exceeds that of domestically consumed natural gas and even coal due to energy-intensive liquefaction and transportation processes, with GHG emissions ranging from 44 per cent to over double that of domestically produced coal for the average cruise (travel) distance of an LNG tanker. Moreover, the global average of Methane leaks resulting in fugitive emissions in natural gas is said to be between 2 per cent and 3 per cent. This is worse for the climate than the GHG emissions.
All this combined with the fact that methane emissions from the oil and gas sector are said to be vastly underreported, clearly shows that natural gas is not “very clean” as the agencies claim it to be. In the pursuit of cleaner energy, evaluating the true climate impacts of natural gas and coal remains crucial for informed decision-making in the transition away from fossil fuels.
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