According to the Climate Council, transport is Australia’s third largest source of greenhouse gas emissions, with the highest rate of growth. Cars are responsible for roughly half of Australia’s transport emissions. An international scorecard comparing 23 of the largest energy-using countries, ranked Australia second-worst for transport energy efficiency due to high emitting cars, and the lack of greenhouse gas emissions standards in place for cars or heavy vehicles; the relatively high distances travelled by car per person, compared to similar countries; low use of public transport (12% of trips); and low ratio of spending on public transport compared to roads.
Fuel Combustion: The primary cause of emissions from cars is the combustion of fossil fuels. Internal combustion engines in traditional vehicles burn unleaded petrol (ULP) or diesel, releasing carbon dioxide (CO2) and other pollutants into the air.
Incomplete Combustion: Inefficient combustion processes can lead to incomplete burning of fuel, resulting in the emission of harmful pollutants such as carbon monoxide (CO) and nitrogen oxides (NOx). These pollutants contribute to air quality issues and environmental degradation.
Idling Engines: Cars left running while stationary contribute to unnecessary emissions. Encouraging responsible driving habits and minimizing engine idling helps reduce the release of pollutants, conserving fuel and improving air quality in our community.
Vehicle Maintenance: Poorly maintained vehicles can emit higher levels of pollutants. Regular maintenance, including timely tune-ups and proper care of exhaust systems, is crucial in ensuring cars operate efficiently, minimizing emissions and promoting a cleaner environment for everyone.
According to the Climate Council, cars in Australia emit the same amount of greenhouse gases as Queensland's entire fossil fuelled electricity supply.
Vehicle emissions refer to the gases and particles released into the air as a result of the combustion of fuel in internal combustion engines. They are called direct emissions, or scope 1 emissions, because the pollution occurs at the same place as the activity is performed (i.e., out the back of the vehicle!)
There are two types of emissions that impact on the environment, air quality and human health: greenhouse gas emissions and air pollutant emissions.
The most common types of greenhouse gas emissions from fuel combustion is carbon dioxide. They also produce methane. Greenhouse gases trap heat from the sun in the earth's atmosphere, causing the greenhouse effect.
The common types of air pollutant emissions from motor vehicle exhaust are:
Carbon Monoxide: A colorless, odorless gas produced by incomplete combustion of fossil fuels. CO can be harmful, as it interferes with the body's ability to transport oxygen and can lead to adverse health effects, especially in enclosed spaces.
Nitrogen Oxides: These gases, including nitric oxide (NO) and nitrogen dioxide (NO2), are produced when nitrogen in the air reacts with oxygen during the combustion process. NOx contributes to air pollution, smog formation, and respiratory issues. It's a significant component of urban air quality concerns.
Particulate Matter (PM): Fine particles released into the air during combustion, primarily from diesel engines. PM can have adverse health effects, particularly on the respiratory system, and can contribute to air pollution and reduced air quality.