Lifetime theft

Richard Parncutt

August 2025

Richard Parrncutt ICMPC 2012

Burning 1000 tonnes of fossil carbon, or emitting 4000 tonnes of CO2, causes the premature death of a future person from effects of anthropogenic global warming (AGW):
direct heat, starvation, exacerbation of existing diseases, and so on. That's the 1000-tonne rule. It corresponds roughly to different estimates of the human cost of global warming or mortality cost of carbon in the literature (Bressler, Nolt, Parncutt, Pearce), plus or minus a factor of 2. In other words, it lies somewhere between a 500- and a 2000-tonne rule.

The 1000-tonne rule is easy to derive. Burning a trillion tonnes of fossil carbon altogether will cause AGW of 2°C. That will probably cause one billion premature deaths, spread out over a long period of 1-2 centuries. A trillion divided by a billion is a thousand.

AGW could cause existing death rates to increase by 10m/yr for 100 years. The long period of time is partly because the half-life of anthropogenic CO2 in the atmosphere is so long (currently less than a century, but getting longer) and party because humanity is taking so long to get carbon emissions under control.

People in the future who die from effects of global warming
could be very old or very young or anywhere in between. Let's suppose that normal life expectancy without AGW, poverty or other serious stressors is 80 years. If that is the case, the average age of a future person who dies in connection with AGW is 40.

So when we burn 1000 tonnes of fossil carbon, we steal 40 years from the life of a future person. It follows that when we burn one tonne of fossil carbon, producing about 4 tonnes of CO2, we steal 1/1000 of a life. 40 years is 14600 days, so we steal about 15 days from the life of a future person every time we burn a tonne of fossil carbon. That happens every time we take an intercontinental return flight in second class. It's called lifetime theft.

In this way we can estimate the amount of time we steal from a future person whenever we burn fossil fuels. We can then ask ourselves whether that is justified or not, and adjust our behavior accordingly.

Cigarettes

To get the ball rolling, it helps to start with a familiar example: cigarettes. Smoking one of those things steals 10 to 20 minutes from your own life. Not someone else's -- your own. To do that, it takes 5-7 minutes. So you are stealing time at a rate that is 2 to 3 times greater than the time you are spending. Let's call that the Lifetime Theft Factor.

If you want to check out the detail, here is some source literature:
Driving

Let's say you are driving 
an efficient small to medium car at 80 km/h (50 mph), which minimizes fuel consumption per km.
The lifetime theft factor for efficient driving is about 1. It's about half as dangerous than smoking.

Flying

Flying is much worse. The lifetime theft factor is about 25 in economy class and higher otherwise. For every hour that you fly, you typically steal from a future person:
Let's calculate that:
Therefore, the ratio of time stolen to time spent flying is 350/13.4 = 26. For every hour that we fly in economy class, we steal a day from the life of a future person. For background about comparing economy with business and so on, see:
Clearly, flying should be much more expensive (carbon tax). Frequent flyers should be especially penalized. Rationing is a possibility. Beyond that, flying should be reserved for emergencies, and private jets should be banned.

Acknowledgment. This page was inspired by an email exchange with David M. Carter, who developed a similar measure called "flight time factor".

The opinions expressed on this page are the authors' personal opinions.
Suggestions for improving or extending the content are welcome at parncutt@gmx.at.
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