Flying? No Shame in That! The Airplane is a Sustainable Mode of Transport

It's common to come across newspaper articles or blog posts that anxiously report on the ecological impact of airplanes. They cite figures, scientific research, and interviews with authoritative experts: the emerging theses, barely veiled in emphasis, relate to irresponsible use of this mode of transport, accused of polluting more than others or even being one of the main causes of anthropogenic climate change. Some articles even argue the need for social control through the so-called "shame of flight". But is this really the case? What do objective statistical sources say? Should we feel ashamed when boarding an airplane?

To briefly answer these potential dilemmas, it should be noted that air transport is responsible for 2% of global emissions: in other words, self-proclaimed experts omit a relevant piece of information, namely that 98% of emissions are caused by other human activities. In detail, the sector generates:

• 1.9% of greenhouse gas emissions (which includes all greenhouse gases, not just CO2)
• 2.5% of CO2 emissions
• 3.5% of 'effective radiative forcing' – a closer measure of its impact on warming.

(source: www.ourworldindata.org, the first figure refers to 2016, the next two to 2018)

Experts naturally highlight how emissions from aviation have doubled since the mid-1980s. However, they forget to contextualize this data: global CO2 emissions have indeed grown at a similar pace. This means that their share of global emissions has remained stable, around 2% - 2.5%.

Finally, it should be kept in mind that assessing the ecological footprint of transport means is a complex subject, presenting an articulated statistical landscape. Among the many metrics, the one proposed by Vaclav Smil is particularly interesting because it allows comparing different systems based on the energy required to transport a person for one kilometer: 

(source Smil, Vaclav. I numeri non mentono: brevi storie per capire il mondo. Torino: Einaudi, 2021)

Even the analysis of the energy efficiency of transport does not seem to lend credibility to the arguments blaming air travel. It is also interesting to note that these assessments often do not take into account the energy required to build and maintain the basic infrastructure (airports, stations, tracks, roads, etc.), an aspect that significantly impacts the evaluation of different modes used for moving people and goods. The data produced in these analyses often start from assumptions that are not always transparent about the occupancy rate of carriers: it is important to verify this point, relevant for obtaining consistent data. The data too often consider a theoretical maximum occupancy of a train, avoiding the use of a real average rate.

The pollution caused by aviation is one of those topics favored by certain schools of thought, a relic of an era where aircraft contrails were accused of causing global cooling, a theory popular until the early 1980s. In reality, these are subjective narratives that lack significant backing. In this context, shame is certainly misplaced and appeals that use it are not only unhelpful but also counterproductive, as they divert attention from sectors that require more interventions and attention.