A global analysis has verified that electric cars and heat pumps generate less greenhouse gas over their life cycle than their archaic petrol and fossil boiler counterparts, which together account for a quarter of the world’s emissions.
Considering several different climate policy scenarios over the next three decades, European researchers report in the journal Nature that electric vehicles and heaters are the better options in all cases, dispelling claims they aren’t any greener.
“Fears that electric cars could actually increase carbon emissions are unfounded in almost all parts of the world,” says lead author Florian Knobloch, from Radboud University in The Netherlands.
“Electric cars and heat pumps lead to lower carbon emissions overall, even if electricity generation still involves substantial amounts of fossil fuel.”
The researchers simulated 59 regions, including the US, China and most of Europe, which together account for 95% of the global demand for heating and transport.
In 53 of these, emissions from electric cars were found to already be lower than fossil fuel alternatives. The few exceptions included places like Poland, which still rely mostly on coal to generate electricity.
“However,” says Knobloch, “with energy production decarbonising worldwide, the last few debatable cases will soon disappear.”
Countries did vary considerably according to the amount of electricity generated from alternative and renewable sources.
In Sweden and France, for instance, average lifetime carbon dioxide emissions from electric cars are 70% lower than petrol cars, while in the UK they are 30% lower.
The researchers estimate that by 2050 half of the cars on the road could be electric, which would drop global emissions by up to 1.5 gigatonnes per year – equating to those currently generated by the whole of Russia.
For each of the regions in the analysis, Knobloch and colleagues conducted a life-cycle assessment of emissions generated from cars and heating systems, including the production chain and waste processing.
Building on previous research, which has only considered the present situation, they also accounted for the vast range of cars and heating systems available.
The comprehensive analysis simulated three future scenarios. The first two involve continuing with current climate policies or enacting feasible policies in line with the two-degree target set by the Paris Agreement.
The third, a worst-case scenario that the authors say is unlikely, considers what would happen if ambitious targets are implemented for electric cars and heating while overall emissions continue on their current trajectory.
The empirical model includes future consumer technology choices, based on detailed consumer market databases, and the resulting emissions from power generation, transport and household heating using historical observations.
“We combined the resulting scenario projections with bottom-up estimates of life-cycle emissions from producing different technologies and their fuels,” Knobloch explains.
At the study’s inception in 2015, electric cars and heaters both emitted a third less harmful gases than their air-polluting alternatives. Looking ahead, all three tested scenarios looked positive.
Staying on current trajectories would lead to 10% lower emissions globally on average by 2030 and 16% by 2050. If Paris Agreement targets are met, that drops to 44% and 74% lower emissions, respectively.
This also holds true for low-efficiency electric vehicles and heat pumps, which performed better than high efficiency petrol cars and fossil boilers, leaving no doubt about the best way forward.
“Taking into account emissions from manufacturing and ongoing energy use, it’s clear that we should encourage the switch to electric cars and household heat pumps without any regrets,” says Knobloch.
“Even in our worst-case scenario, there would be a reduction in emissions in almost all cases. This insight should be very useful for policy-makers.”
The Royal Institution of Australia has an education resource based on this article. You can access it here.
Natalie Parletta is a freelance science writer based in Adelaide and an adjunct senior research fellow with the University of South Australia.
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