How Many Deaths Will My Flight Cause?

How many future climate deaths are caused by the CO₂ emitted from a typical flight? When expressed in terms of future hours of lives lost per hour flown, the answer is bad. See below.

The Nature paper The Mortality Cost of Carbon (MCC) estimates that, if we later hit 2.4°C of warming, then adding 9,318 metric tons of carbon dioxide in 2020 causes one excess death globally in expectation between 2020-2100. For more explanation, please see How Many Children Can One Oil Depot Kill?

The Flight

Consider a 700-km flight from London Gatwick to Basel, Switzerland. According to https://co2.myclimate.org/en/flight_calculators, a one-way, economy-class flight leads to emissions of 172 kgCO₂ equivalent.

Therefore this flight causes 172 / 1000 / 9,318 = 0.0000185 future deaths.

Most climate deaths are likely to occur in the Global South, where life expectancy is around 70. Let's guestimate that the millions of future deaths caused by man-made climate change cause the victims to lose an average of 35 life-years.

So our flight (averaged over future climate deaths) leads to a loss of 0.0000185 x 35 = 0.000646 life-years, ie 5.7 life-hours.

https://simpleflying.com/how-fast-does-a-boeing-737-fly/ reports that the typical cruising speed of a Boeing 737 is 796 km/h. For simplicity, let's assume the plane travels at its crusing speed for the whole journey. Hence, the journey takes 0.88 hours. If this seems short, according to https://www.flighttimecalculator.org/flightduration the flight time from Gatwick t Basel is 1hr 19mins including 25 mins take-off and landing time.

Scaling this we find:

Flying for one hour causes 6.4 life-hours to be lost in future climate impacts

Notes

It's important to note that this is a central estimate, and the range in the MCC paper is very wide! Please see How Many Children Can One Oil Depot Kill? - Notes & Sources.

That said, this figure is likely to be an underestimate for the following reason:

• The MCC study considers only directly temperature-related deaths; there will be many more deaths that it does not cover, eg from food shortages, drought and forced migration.