Are the zero emissions from electric vehicles really zero?

Written by Plistina Almeida and Simon Welchman


In Australia, more than 55% of NOx and 12.9% of PM2.5 emissions to air that are caused by human activities are due to motor vehicle traffic. Higher concentrations of these pollutants tend to occur in the morning and evening because peak traffic volumes can coincide with times of poor atmospheric dispersion. Motor vehicles also produce greenhouse gases that are responsible for global warming.


Nitrogen dioxide (NO2) and PM2.5 are two air pollutants that are commonly found in cities around the world. Air pollutants are generated by natural causes such as bushfires, wind-blown dust and salt spray and man-made activities such as exhausts of fossil-fuelled vehicles and industrial activities.


Recent projections suggest that the Australian motor vehicle fleet may be close to fully electrical by 2050. Most Australian state governments have committed to generation of 50% of electricity by renewable sources in by 2050. So, will this shift towards Electric Vehicles (EV) and renewables have an impact on the air quality and greenhouse gas emissions for roads, tunnels and busways?


The basics: Do electric vehicles produce emissions? How much less pollution do electric cars emit?

Exhaust emissions from EV are zero. However, air pollutant and greenhouse gases are generated in their manufacture and, if fossil fuels are used, to generate the electricity that they use. Some argue that powering EV using electricity generated by fossil fuels is futile. Whilst this may be the case from a greenhouse gas perspective, it neglects the potential benefits in the reduction in roadside air pollutants, which are likely to be significant from a health perspective.


However, EVs do produce some air pollutants, which are associated with tyre and brake wear.  Such emissions are already produced by vehicles that use fossil fuels.


Researchers estimate that average lifetime emissions of greenhouse gases from EV can “be up to 70% lower than the emissions of petrol cars in countries like Sweden and France (which get most of their electricity from renewables and nuclear), and around 30% lower in the UK” (Knobloch et all 2020 and Harrabin 2020).


What if all cars were electric?

The short answer to this question is that we would see a noticeable reduction in the concentration of air pollutants such as NO2 and PM2.5.


How can Katestone help deal with roadside air pollutants?

Katestone has conducted a large number of air quality assessments of significant road projects in Australia. These assessments have included:

  • Tunnel projects in Queensland, NSW and Victoria
  • Busway projects in Queensland
  • Evaluation of pollutants emitted from major urban roads and regional freeways
  • Design and implementation of air quality monitoring networks
  • Development of criteria and procedures for safely siting facilities for sensitive groups with consideration of road networks (such as child-care centres and schools).


Our team has had extensive involvement in communicating air quality issues with affected communities through its impact assessment work, community meetings and information sessions.  We have also conducted peer reviews for various stakeholders across various stages and aspects of the project and provided advice regarding potential air quality and dust issues, and risk mitigating strategies.


Contact us today to discuss the full range of air quality services that Katestone offers to the road transport sector including impact assessments, pre-feasibility studies, emissions inventory, air pollutant dispersion modelling as well as devising monitoring and mitigation strategies to manage pollution from road traffic.



Harrabin, R. (2020). Electric car emissions myth “busted.” BBC News. [online] 23 Mar. Available at:

‌Knobloch, F., Hanssen, S. V., Lam, A., Pollitt, H., Salas, P., Chewpreecha, U., … & Mercure, J. F. (2020). Net emission reductions from electric cars and heat pumps in 59 world regions over time. Nature Sustainability, 1-11.


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This article featured in the Katestone’s Clear Skies 2021 Winter edition. Click here to view other featured articles.

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