3 ms·
Yes you would. Growth is a result of the differential between the birth rate and the death rate. If the fertility rate stays the same, but lifespan increases, t
by astazangasta 12y ago
Yes you would. Growth is a result of the differential between the birth rate and the death rate. If the fertility rate stays the same, but lifespan increases, there would be a period where the death rate would decrease, at least, until the new stable lifespan is reached. In this period, the population would increase dramatically.
- Brakenshire 12y agoI'm not using exponential as a synonym for really fast, I'm using it to mean an exponential function. If lifespan increases but fertility rate remains low (as in the developed world), you get a very different sort of population growth than each couple having seven children, each of which will marry and have seven children, and so on. If fertility rate stays the same, and adult lifespan increases from 70 to 100, there would be the same number of children born over a number of generations as would have happened anyway, but they would live 40% longer. I presume that would mean a capped one-off 40% increase over the period of 30-150 years (depending on how quickly and equally the global population took up the technology, and how much it relied on preventative treatment early in life). Fertility based population growth would mean exponential increases - so for instance a doubling from 2 billion in 1930 to 4bn in 1970, then 8bn in 2010, 16bn in 2050, 32bn in 2090 etc. I think this "filling out" sort of non-exponential growth is actually a large part of what is predicted over the next 50-100 years (from adults in middle wealth countries getting near Western levels of life expectancy), Hans Rosling talks about it in his "Don't Panic" lecture from a year or two back.