17 Aug 2023

What are the climate impacts of policies for the accelerated conversion of the ICE fleet to electric?

photo_5314705258238296221_y (1)
Louis-Pierre Geffray
Head of Programs


Low-Emission Zones (LEZs) were conceived and designed to address health issues. One effect of implementing these zones is to accelerate the replacement of older internal combustion engine (ICE) vehicles with more modern versions or with electric vehicles (EVs). Would an accelerated conversion of the fleet, brought about by such a scheme or by measures such as “social leasing”, be appropriate in terms of reducing greenhouse gas emissions? When factoring in production impacts, should we not consider extending the lifespan of existing ICE vehicles for as long as possible? This issue is often raised in debates by those who question the relevance of LEZs or the push for vehicle electrification. This Issue Brief attempts to answer these questions?


Key Messages

  • Extending the life of an ICE vehicle only marginally reduces greenhouse gas emissions per additional kilometre travelled, because fossil fuel use (the unavoidable part of emissions) accounts for more than 70% of the impact over the entire life cycle of these products.
  • Extending the life of an EV, conversely, is a major way of reducing greenhouse gas emissions. Encouraging long lifespans for this vehicle type must be the subject of proactive public policy (regulations on battery durability, currently under discussion at the European level, are an important priority in this perspective).
  • When buying a new vehicle, the most environmentally-friendly option for an owner in terms of the lowest greenhouse gas emissions is to replace an ICE vehicle with an electric one as soon as possible (accounting for the impact of vehicle manufacture and assuming that the ICE vehicle could be driven for four more years).
  • Extending the lifespan of an ICE vehicles can only be envisaged for low mileage drivers and on the condition that they switch to electric when the vehicle is eventually renewed. Buying a new, more fuel-efficient ICE vehicle to replace an old one, and then keeping it for 18 years (the average lifespan of vehicles in France) represents the worst option in terms of greenhouse gas emissions.
  • This analysis is an initial response that could be supplemented by a study of environmental indicators in addition to global warming potential: depletion of mineral resources, impact of mining activities, water consumption, etc. Furthermore, the model scenarios intentionally do not consider transport demand, vehicle size or vehicle efficiency, even though action must be taken on all these fronts, because they are undoubtedly intrinsic for the success of the transition.