Wouldn't it get us to 3 billion in 7 hundred years?
Sure would....I had in mind the typical example of a ONE percent per year increase (or negative increase). but we are talking about .1%. Which as you point out takes a little bit longer.
Please don't trust my math...here's a page that explains it better than I can...and it's high school math...despite my own decimal issues.
http://users.rcn.com/jkimball.ma.ultran ... ling_TimesAnd from that site:
Whatever the case, there are grounds for some optimism about future population growth.
The world value for r peaked around 1990 and has declined since. This is a reflection of the decline in total fertility rates (TFRs) in undeveloped countries, presumably as the various factors involved in the demographic transition take hold, e.g.,
* improved standard of living
* increased confidence that your children will survive to maturity
* improved status of women
* increased use of birth control measures
The projection of future TFRs in the graph above (from the Population Reference Bureau) predicts that the less developed countries of the world will reach replacement fertility around the year 2020. In fact, they will probably reach it sooner because by 2006 the world TFR has dropped to 2.7. Even so, will the world reach zero population growth (ZPG) then?
This graph (based on data from the UN Long-Range World Population Projections, 1991) gives 5 estimates of the growth of the world population from now until 2150, assuming that TFRs decline from the 1991 value of 3.4 to the values shown.
* A value of 2.06 will produce a stable population of about 11.5 billion.
* A value 5% below that (1.96) will cause the population to drop back to close to its present value (6.1 billion) while
* a value of only 5% above (2.17) would produce a population of over 20 billion and still rising.
A consensus?
The several agencies that try to predict future population seem to be moving closer to a consensus that:
* the world population will continue to grow until after the middle of this century
* reaching a peak of some 9 billion (up from today's 6.5 billion) and then
* perhaps declining in the waning years of this century.
And you'll see from there that there are a lot of other factors. Really what matters is the size of the population within their reproductive years...but the rule of 70 is an easy way to sketch out some basic predictions. If you aren't decimal challenged, that is.
As for birth control and education...I'm all for it, wintler. How far do you think you will reduce the population in this way? But I love this:
What about comprehensive education, contraception, stop-at-one incentives and infant health? All been advocated, haven't seen you give them a moment of your bandwidth. I have no costed plan but they would be modest in comparison with additional infrastructure spending they would demand or current military spending.
But that's the whole point, wintler. It is the countries in extreme poverty which have the highest birth rates. I have been suggesting that the way to deal with that is to address the poverty, not the genitalia. It is the hold over the world that the megacorporations and military industrial complex has which is the problem. In order to do what you suggest, you'll need to severely disrupt that control...they like dictators who drain local economies. They insist on the removal of social safety nets to allow for "structural re-adjustments" (i.e. any barrier to economic exploitation.) They like war.
Why do you think the U.S. hates Cuba so much? Because they show it is possible to resist this.
So ironically, even if you just want to address reproductive issues in poor countries, the changes you'd have to make would necessitate the kinds of economic changes that ultimately would lead to a decreased birth rate and (more importantly) higher quality of life...WHETHER OR NOT you specifically addressed reproductive issues.
Note again from the article above why the birth rates (or total fertility rates as the article puts it) are declining in some of the "undeveloped" world:
* improved standard of living
* increased confidence that your children will survive to maturity
* improved status of women
* increased use of birth control measures
Which suggests to me that improving the standard of living, the health care system and the status of women (they have to be in a situation where they are given the choice to use birth control measures) are the ways to go.
I would simply add to that that we must then also look at the economics of food production and reverse all of the policies that destroy local farming economies and all of the other things I mentioned in a previous post.
Can the earth support 50 billion? Well, who knows what we will be capable of in the future...but that could only happen if we lived in a world not run by the whims of the uber rich. But that's irrelevant anyway, as all trends suggest we will top out at 9 or 10 billion. ESPECIALLY if we continue to improve the quality of life in poor countries.
With a more just distribution of resources, we could easily feed everyone on the planet right now, for all the reasons I've outlined. In addition, if you address the real issues which lead to hunger in the world, you will also be reducing the population growth rate as well.
[Not wanting to shock people, I should add, that's "only" 9 degrees F above the average daily max temp where I am].
