Mobile phones have very short lifespans—on average, around two years. So even though producing a single phone may not seem to require many resources, the total energy embodied in their production was estimated in 2015 at about 1 exajoule per year of use. In the same period, the production of cars embodied about 0.72 exajoules per year of use. This comparison demonstrates the destructive power of short-lived products when multiplied across the entire economy.