The environmental impact of human activities is stark, particularly when it comes to travel. Pioneering research by experts at the University of Leeds has shed light on the often underestimated emissions associated with long-distance travel. This groundbreaking research offers a compelling new perspective on the significant role travel plays in exacerbating the climate crisis.
The data reveals that while UK residents make fewer trips of more than 50 miles, these longer journeys are responsible for a disproportionate share of carbon emissions (70%). This divide is even more stark for international travel, which accounts for just 0.4% of total travel but contributes 55% of emissions.
Recent findings published in the journal Nature Energy suggest that reducing long-distance travel may be a more effective approach to reducing emissions compared to current efforts focused on local travel and commuting.
Although domestic car travel, both long and short, has declined slightly over the past 25 years, there has been a notable increase in international air travel, largely due to increased leisure travel and visits to friends and family.
“The scale of the impact of long-distance travel is indeed very significant. The fact that just under 3% of our journeys are responsible for around 60% of the kilometres travelled and 70% of the emissions shows how important long-distance travel is in the fight against climate change,” said Dr Zia Wadud of the university’s Institute of Transport Studies and School of Chemical and Process Engineering, who led the research. “It is worrying that long-distance travel, especially flights, is increasing. However, it also offers opportunities.”
The research team developed a new metric, emissions reduction sensitivity, to identify changes in travel behavior that can maximize carbon reduction with minimal impact on people and travel. Their findings reveal that replacing all car trips under 13 kilometers with walking or cycling could result in a significant 9.3% reduction in carbon emissions.
This change would, however, require changing about 55% of all trips, with car trips being the majority in the local area. The calculated sensitivity to emissions reduction for this change is only 0.17, the lowest in the study.
Shifting all flights under 1,000 miles to train would result in a 5.6% reduction in emissions, with only 0.17% of journeys affected, giving a sensitivity value of 33.2.
Limiting everyone who currently flies internationally to one return flight per year would yield a value of 158.3, as very few trips would be affected.
The researchers stress that these potential changes are only suggestions intended to prompt us to recognize and reassess the impact of our long-distance travel rather than specific policy recommendations.
Dr Muhammad Adeel, co-author and now a fellow at the Centre for Transport and Society at the University of the West of England, added: “While efforts to shift local travel to more sustainable modes of transport are really positive, by omitting aviation emissions from national statistics – as is currently the case in almost all countries – we are missing the whole picture and ignoring a large part of the problem.”
The researchers are also optimistic that their findings can serve as a catalyst for policymakers to consider changes in how resources are allocated when it comes to tackling the environmental impact of travel.
The information was collected from the Department for Transport’s National Travel Survey and the International Passenger Survey, conducted by the Office for National Statistics.
The study also gives the public insight into the potential impact of behavior change.
Dr Wadud added: “The important thing, both politically and personally, is to prioritise relatively small, long-distance trips – especially flights – in order to achieve the greatest reductions.”
Journal reference:
- Zia Wadud, Muhammad Adeel and Jillian Anable. Understanding the important role of long-distance travel in passenger travel carbon emissions. Nature Energy, 2024; DOI: 10.1038/s41560-024-01561-3
