Transportation accounts for approximately 16% of global greenhouse gas emissions, making it one of the largest contributors to climate change. The way you choose to get around, whether by car, train, bus, or bicycle, has a significant impact on your personal carbon footprint.

Comparing Transportation Emissions

Here is how different modes of transportation compare in CO2 emissions per passenger kilometer, based on data from the European Environment Agency:

• Domestic flight: 255 g CO2 per passenger-km
• Petrol car (single occupant): 170 g CO2 per passenger-km
• Diesel car (single occupant): 165 g CO2 per passenger-km
• Motorcycle: 103 g CO2 per passenger-km
• Bus (average occupancy): 68 g CO2 per passenger-km
• Electric car (single occupant, average grid): 50 g CO2 per passenger-km
• Rail (national average): 35 g CO2 per passenger-km
• Electric bicycle: 5 g CO2 per passenger-km
• Cycling / Walking: 0 g CO2 per passenger-km

The Electric Vehicle Revolution

Electric vehicles (EVs) produce significantly fewer emissions than their petrol or diesel counterparts, even when accounting for electricity generation. The IEA Global EV Outlook reports that over the full lifecycle, EVs typically produce 50-70% fewer emissions than conventional vehicles.

The environmental benefit of EVs depends heavily on the electricity grid. In regions powered primarily by renewables, EVs are dramatically cleaner. Even on coal-heavy grids, EVs generally outperform combustion engines due to the higher efficiency of electric motors.

The Case for Public Transit

Public transportation is one of the most effective ways to reduce personal transportation emissions. A full bus replaces approximately 40 cars on the road. The American Public Transportation Association estimates that public transit saves 63 million metric tons of CO2 annually in the United States alone.

Carpooling and Ride-Sharing

If public transit is not available, carpooling dramatically reduces per-person emissions. A car with four occupants is roughly four times more efficient per passenger than a single-occupant vehicle. Even sharing with just one other person halves your commuting footprint.

Active Transportation: The Zero-Carbon Option

Walking and cycling produce zero direct emissions and offer substantial health benefits. Cities investing in cycling infrastructure, like Copenhagen and Amsterdam, have seen significant reductions in transport emissions alongside improved public health outcomes.

Track Your Transportation Emissions

Climate Tally's calculator includes dedicated categories for commuting, owned vehicles, and land and sea travel. By logging your transportation habits, you can identify which trips contribute most to your footprint and find opportunities to switch to lower-carbon alternatives.