Lifetime greenhouse gas calculator for cars in the US and Canada
Electric vehicles are often seen as an excellent solution to reduce GHG emissions and mitigate climate change. Scientists show that the issue is much more complex, and must take into account a multitude of factors.
GHG emission reduction is increasingly present in the news and daily discussions. Impacts of climate change are already being felt in our daily lives with the increase in extreme weather events, which leads to individual efforts to fight climate change. Those are often confronted with the information available on key actions to reduce GHG emissions. In this sense, the purchase of an electric car is seen by many as a key action in the fight against climate change, while others say that these will have a greater environmental impact than gasoline-powered vehicles. In this sense, this tool aims to demystify the environmental footprint by comparing gasoline and electric vehicles.
There is no clear answer
Accounting for GHG emissions of a gasoline-powered car and an electric car depends on several variables, which make it impossible to obtain a simple answer. For example, the size of the vehicle, energy efficiency, quality of the electricity used, diesel or gasoline-powered vehicle, lifetime expectancy vehicle, batteries quantity, etc. are all variables that can influence the emissions of either car type. In order to make an interesting and relevant comparison, the study considers two similar passenger vehicles, such as a gas vs electric Ford Fusion. The parameters evaluated now only relate to the location of vehicle use, which can have a decisive impact on GHG emissions.
It varies between regions
Electricity consumed by electric cars comes from different energy sources, in function of the region or grid it is consumed. In some regions, where electricity comes mainly from renewable resources, a small amount of GHGs is generated by electricity consumption and car usage. For other regions, the electricity comes from coal and other non-renewable resources, thus increasing the emissions of electric vehicles. Considering an energy loss in converting fossil fuels to electricity, and then another energy loss in converting the electricity to mechanical energy, it can become inefficient and highly emissive to use electricity to travel, and therefore electric vehicles in some regions. The map below demonstrates that GHG emissions vary greatly between states, which makes electric cars more or less effective in reducing GHGs. As an example, using an electric vehicle in Missouri will have a different impact on climate change than in Washington DC.
What about GHG emissions from production?
Emissions from the production of a gasoline vehicle and an electric vehicle, for similar size models, differ mainly in the batteries. A long-range electric vehicle uses a large proportion of batteries, which can become the main source of emissions during production. It is also important to discuss the problems related to the use of rare materials in batteries.
What about car usage?
Key constants used for the calculations are based on statistical studies and represent an average passenger car. As an example, the total distance over the lifetime of a car has been estimated at 314,000km, but this can vary from one model to another and the type of use will also have an impact on the longevity of the vehicle. At the time of purchase, an electric vehicle emits more than a fuel vehicle because of the production of the battery. The use of the vehicle is generally less polluting for an electric vehicle. It is therefore essential to estimate the vehicle’s lifespan, as it has a high influence on final results.
Impact of electricity decarbonization on the choice of buying an electric or gasoline car
The Biden administration, with its infrastructure investment and electricity decarbonization plan, its climate ambitions and commitments, suggests that the electric grid will improve in the coming years. It is possible that currently, in some states, buying an electric vehicle does not result in a significant emission reduction, but the grid’s evolution in the upcoming years will favor electric vehicles. The choice to buy an electric car may therefore also be based on its life expectancy. Low annual usage and a long-term objective of keeping the vehicle can favor the purchase of an electric vehicle.
Other environmental impacts not covered in the study
Vehicle batteries are mainly made of lithium nowadays. Producing lithium has a high impact on the environment, as it depletes rare metals, destroys the ecosystem, and adds long-term insecurity on shortage and disponibility. Thus to consider the benefits of an electric car is also to consider the whole lifecycle on more aspects than only GHGs.
Favorize public transport to all types of individual vehicles
The study made it possible to analyze and compare the environmental impact of personal vehicles. On the other hand, to take the reflection further and analyze the efforts necessary to mitigate climate change to well-below 2C, it becomes necessary to carry out a drastic reduction in GHG emissions. At this level, only states with completely carbon-free electricity will be able to allow users to use electric cars in order to mitigate global warming. To this end, public transit is becoming one of the only viable solutions currently available to drastically reduce emissions. In this sense, reduction of transport, telework, use of train and the bus are all highly effective solutions for mitigating transport emissions.