Over short to medium distances, walking or cycling are nearly always the lowest carbon way to travel. While they're not in the chart, the carbon footprint of cycling one kilometer is usually in the range of 16 to 50 grams CO₂eq per km depending on how efficiently you cycle and what you eat.

In 2026, the modes of travel with the smallest carbon footprint remain walking and cycling, which produce virtually zero emissions during transit. For motorized travel, the Eurostar is the champion of sustainability, emitting only about 4g of CO2 per passenger kilometer—roughly 97% less than a short-haul flight. National rail services follow closely at approximately 35g/km. If you must travel by road, a fully occupied electric vehicle (EV) or a high-capacity coach/bus are the greenest options. Avoiding short-haul flights is the single most impactful choice for travelers, as these have the highest emissions per kilometer. Sustainable travel in 2026 is increasingly defined by "slow travel," where the journey itself via rail or sea is prioritized over the speed of aviation to minimize environmental impact.