What Will Be the Impact of Seven Billion People?

On Halloween this year, the world’s population will hit seven billion — or so estimates the United Nations Population Fund. Spooky, considering we hit six billion only a little more than a decade ago. Elizabeth Kolbert offers a brief history of population growth in a recent New Yorker article:

Depending on how you look at things, it has taken humanity a long time to reach this landmark, or practically no time at all. Around ten thousand years ago, there were maybe five million people on earth. By the time of the First Dynasty in Egypt, the number was up to about fifteen million, and by the time of the birth of Christ it had climbed to somewhere in the vicinity of two hundred million. Global population finally reached a billion around 1800, just a couple of years after Thomas Malthus published his famous essay warning that human numbers would always be held in check by war, pestilence, or “inevitable famine.”

Of course, we all know that Malthus was a little off the mark. But as the world’s population continues to grow (to perhaps 10 billion and growing by 2100), Kolbert raises concerns about the planet’s ability to sustain all that life: “As many, including Bill Gates, have pointed out, just to keep per-capita food production constant in the coming decades will require a second ‘green revolution.'”  Part of what made the first green revolution possible was a sharp increase in the use of phosphorus-rich fertilizers,” she writes.  “Thanks to this increased use, experts say, reserves of phosphorus are now being exhausted…Other essential commodities that could similarly run short include oil, water, and arable land.”


But if you look at the rate, it is actually the same or even declining depending on how you see it. Eg, the population increased from 1 billion to 2 over ~130 years to 1930. Subsequent increases by a billion have occurred over 30, 14, 12, 13 and 12 years (1930, 1960, 1974, 1986, 1999 and 2011 respectively). (numbers fromWoflram alpha). So we are roughly adding a billion people every 10 to 14 years now despite the increase in the baseline population.


Getting the major religions to realize birth-control is a necessity should get us started.


it's not religions. there's so many different religions in the UK and US etc but they're not the ones producing all the population. it's less developed, and uneducated countries that don't know what harm a massive population will do to the planet. so it's actually undeveloped countries. they NEED that education.


Do you seriously suggest that the declining birth-rate in the western world is a consequence of us "knowing what harm a massive population will do to the planet"? It's news to me that any western nation is actively trying to minimize population growth. (Only China really did/does that - admittedly for reasons of fear of over-population in relation to their food-production) And hardly any individuum's sense of "responsibility for the world" will go as far as to abstain from having children they personally so much want to have.
That being said, I do agree that there is a convincing point in arguing that education and development has a lot to do with a decline in birth rate - but that happens on a micro-level, as educated individuals tend to have fewer children: arguably, that is because they tend to "enjoy life" and reap the benefits of their education themselves (rather egotistically) and not put their efforts so much into having many children as a "substitute" and hope for them having a better life than they have themselves.
Culture plays a role in this, but culture is obviously a dynamic structure and changing with education.
By the way, I am not saying that having children is not a value in itself for many, but there is always a trade-off between other "joys" and the joy of having children - for many in the "western world", the huge number of available alternatives to experience happiness (enhanced through cultural bias for conumption and against large families) just creates a strong bias against having (many) children.


Mike B

Soon rising incomes and women's rights will begin to put major downward pressure on population growth. Where such effects lag, rising food costs will help establish equilibrium through attrition.


Brutal, but correct.

Eric M. Jones

Some studies are optimistic, saying that rising standards of living, health and education tend to be accompanied by lower population growth.

I am not so optimistic... Get ready for Soylent Green.

Mike B

Russia is losing about 1 million people per year. If current trends continue Japan will simply run out of people in a few hundred years. The only thing helping the United States keep its population growth positive is immigration. Where do you see all these new babies coming from? Don't forget as soon as virtual reality becomes cheaper than dating there will be almost no reason to have biologic children anymore.


Why would we want to keep population growth positive? So we can cram yet more people into the human equivalents of battery chicken farms and cattle feedlots?

Mike B

There's a big difference between constant and decline, and both come with major problems with pension and old age medical care plans.

Carlos A López

Last time I looked, phosphorous was not the limiting factor, at least not for a bunch of phosphorous experts...

What I think is that water and land will continue to put stronger pressures, becoming more often the limiting factors (they are already in many places. For one, look at the Ogallala in the US). The main challenge is to improve non-irrigated agriculture in developing countries, where the stronger potential resides. It is not to be done with a second green revolution, which was not green at all (we were sowing with oil, basically). Improving rainfed ag could not only help produce enough food for the 9 billion people of one generation ahead , but can help alleviate poverty. GMOs could play a big role on this, although my main concern with them is corporate control over local lifestyles.

Besides better rainfed ag, the other thing that can really help is to have more conscious diets. The power of shifting diets could be underestimated. It seems just not possible as of now for everyone in the world to keep a meat-based diet. I'm not saying everyone should become vegetarian or vegan. No. I also love my burger. But a conscious diet (low-meat, for starters) can have a great multiplier effect on saving some land and water per calorie consumed. I support elimination of subsidies on water in agriculture. We need to face better food prices (that better reflect some of the most challenging scarcities) to make better food decisions in a very crowded world...



Nature as it is truly intended has its way of weeding out enough animals ( remember, humans still are animals, no matter what you may believe ) in order to make life sustainable for all life on the planet. We see stage 4 countries continue to lose more and more people every year, except the U.S. because of our immigration problem. Though the world is actually VERY unpopulated, there are too many people living the lifestyle of paycheck to paycheck instead of farming to make the earth support the life that is currently on it. Once it gets to be too much, food supply goes even further down, thus making people die off. That's the truth people. We can't fight it.

Eric M. Jones

@Mike B:

"Russia is losing about 1 million people per year."
--They all live in Los Angeles

" Japan will simply run out of people in a few hundred years."
--They will have millions of robots.

"The only thing helping the United States keep its population growth positive is immigration."
--Buenos Dias!

"Where do you see all these new babies coming from?"
--You don't know where babies come from?


It seems that smarter population control would be advised. The issue is the drain on resources, we have to many people that don't produce or do anything for that matter and expect everything. These people also reproduce, and expect others to take care of their clones. There should be a means test if you don't pass a contraceptive should be administered. Zero population growth every two people has one child for one generation watch how the planet recovers.


Meeting the demands of more global mouths to feed is a good opportunity for American agriculture.


The population is already out of hand. I just saw the Australian parents of the seven billionth child on television. They were ecstatic. Australians seem to want more people to populate their land. What they don't seem to realize is that every child leaves a carbon footprint.
Freshwater is getting more scarce. Arable land, 10 to 20% of the planet's land mass, is disappearing through erosion at the rate of tens of thousands of square miles per year. According to research at Oregon State University, the average American mother leaves a carbon footprint of 450 years per child. This is a disaster for climate change.
Organizations and individuals have been warning us about the dangers of overpopulation. A little over a year ago ScienceDaily noted that it was the major world problem-- with climate change second. It is certainly recommended that people familiarize themselves with all of the problems of overpopulation. The free websites at overpopulation.org, which keeps us current on news of the problem, and the free e-book series "And Gulliver Returns" --In Search of Utopia-- (http://andgulliverreturns.info) that not only goes into the details of the problem but also explains the ethical and psychological barriers to changing people's behavior, are must reads.
Naturally business interests want more customers, political interests want more workers to support the welfare systems and more warriors to protect their ways of life, and religions need more souls to save. It is sad that we can't see the cliff as we follow our lemming-like brothers into oblivion.


The Regular Joe

I don't know and I'm not sticking around to find out. something has got to give