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Just because the growth rate isn't constant, does not make it not exponential. I do acknowledge that there are smart people forecasting the end of exponential

Just because the growth rate isn't constant, does not make it not exponential. I do acknowledge that there are smart people forecasting the end of exponential growth, but who is to say a cultural or technological phenomena will not change this path? It is currently exponential, anything else is a lie, and I don't even know what the intentions would be of someone perpetuating such nonsense. Now there will easily be at least a whole generational period in which we don't really know for sure if we have leveled off, that is just the nature of human reproduction, seems safer to wait at least 1 generation before we have declared victory on our biggest enemy.

ch4s3 5y ago
The current population growth rate globally is 1%[1], which is definitionally not exponential. World population has doubled since 1970, but the rate has been declining since. [1]https://www.macrotrends.net/countries/WLD/world/population-growth-rate https://www.macrotrends.net/countries/WLD/world/population-g...
- bliteben 5y ago
  It would be exponential if the net growth rate was 0.1%. If your savings account produces 0.1% interest that is still exponential growth. According to the rule of 70 (https://en.wikipedia.org/wiki/Rule_of_72 https://en.wikipedia.org/wiki/Rule_of_72) it would double in 700 years. That is exponential!
  - ch4s3 5y ago
    The growth rate is trending down and will probably go negative, it's unlikely to ever double again over any time horizon we can reasonably project.
    - bliteben 5y ago
      I think this would be a good thing, but if it were reality, I think many countries would encourage births before we got even close to net 0. This part we cannot really know. Singapore is just one example that has been discouraging population increase then switching to encouraging population increase. https://en.wikipedia.org/wiki/Population_planning_in_Singapore https://en.wikipedia.org/wiki/Population_planning_in_Singapo... Yet there is still a net increase during all this time. https://www.macrotrends.net/countries/SGP/singapore/population https://www.macrotrends.net/countries/SGP/singapore/populati... I think asking the world to agree on something this potentially controversial, when you and I can't even agree on the nature of the increase, is asking too much.
kortex 5y ago
> Just because the growth rate isn't constant, does not make it not exponential. That's literally what makes it not exponential (I.e. when it falls low enough that it is no longer proportional to the derivative). Sigmoid functions, catenary functions (hyperbolic trig), even the complex exponential (regular trig), and the like all have exponential terms. We don't use the term "exponential growth" in any of these cases unless there is growth without bounds - aka the real coefficients are positive.
- bliteben 5y ago
  To argue anything other than its exponential is to zoom into an area of the curve that is meaningless. https://en.wikipedia.org/wiki/Estimates_of_historical_world_population#/media/File:Population_curve.svg https://en.wikipedia.org/wiki/Estimates_of_historical_world_... I found the actual population estimate he seems to be referencing are from the Lancelet https://en.wikipedia.org/wiki/Projections_of_population_growth#Other_projections https://en.wikipedia.org/wiki/Projections_of_population_grow... There are enough referenced facts on that wiki page to know that is not a certainty. Human population is obviously not strictly exponential, as there have been worldwide phenomena that lower it globally, and these will happen again in the future, but if the net growth rate is even 0.1% it is not linear, it is exponential. Only when the growth rate equals the replacement rate (deaths) will it suddenly be static, but if it increases even a hair over that its exponential at that moment (because new humans produce more new humans). Also as we know from microbiology human population with finite resources can't be exponential in the long run as resources will limit it, so sure its not an exponential function because it obviously is a logarithmic function (likely with a whole other side to the graph once it reaches its peak). Sure maybe we are smarter than this, but it does seem like a leap to get there. So yes technically you are 100% right human population is not and cannot be exponential, it just has been for the past few centuries, and there isn't a good reason to expect it not to be in the future.

ch4s3 5y ago

The current population growth rate globally is 1%[1], which is definitionally not exponential. World population has doubled since 1970, but the rate has been declining since. [1]https://www.macrotrends.net/countries/WLD/world/population-growth-rate https://www.macrotrends.net/countries/WLD/world/population-g...

bliteben 5y ago
It would be exponential if the net growth rate was 0.1%. If your savings account produces 0.1% interest that is still exponential growth. According to the rule of 70 (https://en.wikipedia.org/wiki/Rule_of_72 https://en.wikipedia.org/wiki/Rule_of_72) it would double in 700 years. That is exponential!
- ch4s3 5y ago
  The growth rate is trending down and will probably go negative, it's unlikely to ever double again over any time horizon we can reasonably project.
  - bliteben 5y ago
    I think this would be a good thing, but if it were reality, I think many countries would encourage births before we got even close to net 0. This part we cannot really know. Singapore is just one example that has been discouraging population increase then switching to encouraging population increase. https://en.wikipedia.org/wiki/Population_planning_in_Singapore https://en.wikipedia.org/wiki/Population_planning_in_Singapo... Yet there is still a net increase during all this time. https://www.macrotrends.net/countries/SGP/singapore/population https://www.macrotrends.net/countries/SGP/singapore/populati... I think asking the world to agree on something this potentially controversial, when you and I can't even agree on the nature of the increase, is asking too much.

kortex 5y ago

> Just because the growth rate isn't constant, does not make it not exponential. That's literally what makes it not exponential (I.e. when it falls low enough that it is no longer proportional to the derivative). Sigmoid functions, catenary functions (hyperbolic trig), even the complex exponential (regular trig), and the like all have exponential terms. We don't use the term "exponential growth" in any of these cases unless there is growth without bounds - aka the real coefficients are positive.

bliteben 5y ago
To argue anything other than its exponential is to zoom into an area of the curve that is meaningless. https://en.wikipedia.org/wiki/Estimates_of_historical_world_population#/media/File:Population_curve.svg https://en.wikipedia.org/wiki/Estimates_of_historical_world_... I found the actual population estimate he seems to be referencing are from the Lancelet https://en.wikipedia.org/wiki/Projections_of_population_growth#Other_projections https://en.wikipedia.org/wiki/Projections_of_population_grow... There are enough referenced facts on that wiki page to know that is not a certainty. Human population is obviously not strictly exponential, as there have been worldwide phenomena that lower it globally, and these will happen again in the future, but if the net growth rate is even 0.1% it is not linear, it is exponential. Only when the growth rate equals the replacement rate (deaths) will it suddenly be static, but if it increases even a hair over that its exponential at that moment (because new humans produce more new humans). Also as we know from microbiology human population with finite resources can't be exponential in the long run as resources will limit it, so sure its not an exponential function because it obviously is a logarithmic function (likely with a whole other side to the graph once it reaches its peak). Sure maybe we are smarter than this, but it does seem like a leap to get there. So yes technically you are 100% right human population is not and cannot be exponential, it just has been for the past few centuries, and there isn't a good reason to expect it not to be in the future.