The private transport sector is among the main culprits of greenhouse gas emissions. Decarbonisation is therefore essential to achieve the objectives of the European Green Deal, but for the efforts of the coming years to have a concrete effect on climate change, it is important to intervene where sacrifices can really make a difference. In fact, not all journeys pollute in the same way. And a new study published in Nature Energy reveals that there is an incredible disproportion between the impact of short-distance and long-distance journeys: journeys longer than 80 kilometres are in fact responsible for the vast majority of emissions produced by private transport, despite representing a minimal fraction of the journeys made by the population annually. In short, rather than on commuters, we should intervene on leisure and business trips made by plane.
The research was carried out by the University of Leeds, and is based on data collected from various institutional censuses of the movements of the inhabitants of the United Kingdom. Although it therefore photographs the English situation, the results are almost certainly comparable with those that would be found in a nation like Italy, given that the trend of emissions produced by private transport in the last 20 years is almost identical in almost all large Western countries.
Compared to other similar research, the University of Leeds’s strong point is that it calculated not only emissions related to internal travel, but also those produced by international travel, often omitted from national statistics. And it is in this way that the true weight of long-distance travel emerges: trips of over 80 kilometers represent 3% of all trips made annually by the English population, but account for almost 70% of emissions from the transport sector, and international travel, which represents just 0.4% of trips, causes as much as 55% of emissions.
While it is therefore important to also act on local travel and urban traffic (where many of the current efforts for decarbonisation are concentrated), encouraging walking, the use of bicycles and the use of public transport, it is in the area of long-distance travel – mainly made for business and pleasure – that even small changes can make a real difference.
In this sense, the authors of the study have made several simulations. If all the trips under 12 kilometers made annually in the United Kingdom by car were transformed, for example, into trips on foot or by bicycle, there would be a 9.3% reduction in greenhouse gas emissions from the transport sector. This is no small goal, but it would require changing a good 55% of all annual trips of English citizens.
By contrast, moving all air journeys shorter than 1,600 kilometres to rail would reduce emissions by 5.6%, but would only affect 0.17% of the population’s annual travel. And if we were to ban (or at least discourage) more than one return flight abroad per year for every British citizen, the effect would be a 33% reduction in greenhouse gas emissions, which would only affect 0.21% of annual travel. That’s more than what would be achieved by converting the entire UK car fleet to electric vehicles, a strategy that would produce a 22% reduction in emissions with the UK’s current energy mix.
The scenarios – the authors of the study themselves underline – should not be taken as concrete proposals, but only as theoretical examples that help to understand the actual, and overlooked, impact of long-distance travel on greenhouse gas emissions. “The important thing – explains Zia Wadud, a researcher at the University of Leeds who coordinated the study – is that both for environmental policies and on a personal level, priority is given to interventions on long-distance travel, and especially on air travel, to obtain the greatest possible reduction in emissions”.