In the chart here we see global transport emissions in 2018. This data is sourced from the International Energy Agency (IEA).
Road travel accounts for three-quarters of transport emissions. Most of this comes from passenger vehicles – cars and buses – which contribute 45.1%. The other 29.4% comes from trucks carrying freight.
Since the entire transport sector accounts for 21% of total emissions, and road transport accounts for three-quarters of transport emissions, road transport accounts for 15% of total CO2 emissions.
Aviation – while it often gets the most attention in discussions on action against climate change – accounts for only 11.6% of transport emissions. It emits just under one billion tonnes of CO2 each year – around 2.5% of total global emissions [we look at the role that air travel plays in climate change in more detail in an upcoming article]. International shipping contributes a similar amount, at 10.6%.
Rail travel and freight emits very little – only 1% of transport emissions. Other transport – which is mainly the movement of materials such as water, oil, and gas via pipelines – is responsible for 2.2%.