How long until the population of the world reaches 8 billion, 10 billion and 15 billion?

Question

8 Billion may be the carrying capacity of the world, so how long until we reach that number? Others say 10 to 15 billion.

Answer 1

They talk about that in An Inconvenient Truth. We should hit 8 billion in less than 20 years. Scientists talk about how demographics are changing where high mortality rates/high birth rates are shifting to low mortality rates/low birth rates. So potentially the world will never reach 10 or 15 billion people (hopefully). It should cap at a little more than 9 billion.

Answer 2

The population may go past the predicted 8 billion carrying capacity, but when it does (in maybe 30 years?) there will be war for territory and food. Each person's survival instinct will force them to plunder and steal from anyone who has any food.

Here's an example of how fast populations can grow even where AIDS is rampant: The population of Uganda has gone from 5 million to 25 million in just 50 years. That is 5 times as many people as just 50 years ago. Try multiplying the world population of 6 billion by 5 and see how many people there might be in the world in 50 years if we don't all kill each other.

Answer 3

Unknown. There are guesses, but only guesses based upon past and current death and birth rates. It varies by country, region and many other factors. Crime rates are included in some models. In some places in Africa, 25 percent of the population has AIDS which is incurable at this time. Good luck guessing. If a cure is found for AIDS and other diseases, then that will drastically change the time factor for population increase. Other models include education levels by region. The more of a population which can read, the lower the birth rate. That's the theory anyway.