Measuring climate impact of vehicles must go beyond the tailpipe

Introducing new energy technologies in road transport will mean the current method of measuring the climate impact of vehicles will become increasingly inadequate, says the LowCVP.

A new report, Life Cycle CO2e Assessment of Low Carbon Cars 2020-2030, shows how total life cycle CO2e emissions will change for different vehicle technologies in the future and estimates how the balance of emissions will alter for different stages in the life cycle for the varying technologies.

Through the report, the LowCVP aims to facilitate the first steps towards ‘beyond tailpipe’ measurement.

Despite roughly 80% of greenhouse gas emissions occuring during the ‘in-use’ phase of a vehicle’s life, the introduction of plug-in electric vehicles, which the Committee on Climate Change are targeting 1.7 million to be on the road by 2020, means that more of the total carbon emissions from cars and other vehicles will occur at the power station, and during the production and disposal of vehicles and fuels.

The report builds on an earlier study that shows future CO2 equivalent metrics for passenger cars need to go ‘beyond the tailpipe’ and include whole life cycle emissions to fully account for environmental impacts.

It shows that there are a range of potential routes to deliver significant carbon reductions, including both increased electrical mobility with battery vehicles and plug-in hybrids but also low carbon liquid and gaseous fuels. However, current measurement methods do not reflect the real impacts.

LowCVP managing director, Andy Eastlake said: “This new report indicates that it is time to move on from the current tailpipe carbon measure, but whole vehicle life cycle analysis is a very complex process and further work is needed.

“With the in-use phase continuing to dominate vehicle impact for at least the next decade the LowCVP is calling for the UK to lead the way in incorporating the new test-cycle and a well-to-wheel approach to fuel consumption and vehicle efficiency to provide both industry and consumers with better information on the carbon impact of their vehicles,” he added.

Evidence is showing that manufacturers are already beginning to turn more of their attention to vehicle component materials and production processes. The materials used in production have differing amounts of embodied carbon and their choice of lightweight steel and aluminium, for example, also impacts on emissions occurring during the operation phase.

The report says that the clear trend is that the use of tailpipe CO2 emissions as an established comparator for different vehicles will become less effective, and almost irrelevant in terms of identifying the true carbon profiles and reduction potential, for future vehicles.

It also stresses that with ambitious policies, reductions in excess of 60% in lifetime CO2e impacts can be achieved by 2030 through a combination of factors from the production phase, use phases and end-of-life phase.

In addition to a greater emphasis on the embodied impacts of the vehicles, recycling/re-use of high-impact vehicle components such as electric vehicle battery packs may have the potential to contribute significantly to decarbonisation efforts of the embodied impacts of future vehicles.

The LowCVP Chair, professor Neville Jackson said: “To select the most appropriate future technologies and products, we need to take a more holistic view of their environmental impacts and it is increasingly clear that we need to look beyond the tailpipe.

“However, it is also evident that many assumptions need to be made to arrive at a broader CO2 measure and significant research work will be needed to explore and agree a new set of measures that we can use.”

Leigh Stringer

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