The carbon footprint of an airline flight could be much greater than what is declared by the main online calculators: this is what emerges from a study published in Communications Earth & Environment which has developed a new tool for calculating CO2 and CO2e emissions that takes into account various parameters ignored by the main calculators, such as the number of passengers in flight, the route followed and the climate impact of contrails. «The numbers are impressive», comments Jhuma Sadhukhan, one of the authors.
Estimates (very) upward. Let’s take a concrete example: for a first class flight from Singapore to Zurich on a Boeing 777, according to ICAO and IATA calculators the passenger’s carbon footprint would be around 3,000 kg of CO2; Google’s TIM (Travel Impact Model) estimate rises to 5,000 kg, while for MyClimate it is 8,000 kg. The new calculator developed by the researchers, called the Air Travel Passenger Dynamic Emissions Calculator (ATP-DEC), raises the figure to over 14,000 kg.
Dynamic calculations and contrails. The ATP-DEC, its creators explain, is a dynamic calculator: instead of thinking that the flight follows an ideal route, it estimates the most probable one by looking at previous flights; the same thing applies to the duration and number of passengers in the cabin.
Another aspect that distinguishes it from other calculators is the fact that it takes into account all the ways in which a flight affects the climate, including the formation of nitrogen oxides produced by the combustion of fuel, the water vapor that forms when the water emitted by the engines remains at altitude, and contrails. “Other calculators do not vary based on aircraft type, fuel or external conditions: our approach is more comprehensive,” explains Sadhukhan. The research team plans to make ATP-DEC available to everyone soon, also launching an app early next year.
