Gas ‘distracts’ from transport decarbonisation agenda – T&E
Using natural gas for transport is as damaging to the climate as burning petrol, diesel or conventional marine fuels, according to a report from the European NGO Transport & Environment (T&E).
The study found that cars running on gas – including renewable gas – produce as much air pollution as petrol cars and marginally less than diesels that comply with real-world emissions limits. The use of liquified natural gas (LNG) in trucks can increase nitrogen oxide (NOx) emissions, depending on the engine type, and can have higher particulate emissions than diesel.
However, LNG has a clear air quality benefit when used in ships, most of which currently use high-sulphur heavy fuel oil. Though T&E notes that similar improvements can be achieved by using low-sulphur marine gas oil or fitting vessels with emissions treatment systems.
‘Based on the latest available evidence, fossil gas used in transport has no meaningful – and when including methane leakage and upstream effects in almost all cases no – climate benefits compared to petroleum-based fossil fuels,’ the report says.
Unburnt methane is known to leak into the atmosphere across the fossil gas supply chain – from extraction to transportation and refuelling – and has a significant impact on the climate profile of natural gas, says T&E. Methane also escapes through the exhaust of engines running on LNG.
Over a period of 100 years, methane is 28 times more potent a greenhouse gas (GHG) than carbon dioxide, and in 2010 it already accounted for 20% of global GHG emissions. A recent US study found that methane leakage rates in fossil gas production could be 60% higher than previously estimated – further damaging the fuel’s environmental credentials.
T&E’s report also stated that the production of biomethane from waste could only supply, at maximum, 10% of transport’s needs. This would also mean that there would be no biomethane available to decarbonise other sectors that use gas, such as residential heat.
‘The idea that we can decarbonise transport with renewable gas is a pipedream,’ says Jori Sihvonen, Clean Fuels Officer at T&E. ‘Pushing biomethane in transport actually makes the climate battle harder by depriving industry and domestic heating of this limited renewable resource.’
Ultimately, Sihvonen says, gas is a ‘distraction’ from the necessary objective of zero-emission transport.