Remarkably, Sri Lanka has a life expectancy that's similar to the USA (shy by a year and a half) with a staggering 88% less resource use and 94% less emissions on a per capita basis.

These metrics are consumption-based:

Raw material consumption:
USA: 32.36 tons per person
Sri Lanka: 3.88 tons per person

CO2 emissions:
USA: 18.35 tons per person
Sri Lanka: 1.03 tons per person

By the way, Sri Lanka has a free, universal public healthcare system.

To put this in perspective, if the world were to converge to Sri Lanka, global average life expectancy would increase by 4.5 years, while global resource use would fall by 70%, and global emissions would fall by 80%.