Population size 'green priority'

[DoYouEverWonder]

6 January 2006

Solving the Earth's environmental problems means addressing the size of its human population, says the head of the UK's Antarctic research agency.

Professor Chris Rapley argues that the current global population of six billion is unsustainably high.

Writing for the BBC News website, he says population is the "Cinderella" issue of the environmental movement.

But unless it is addressed, the welfare and quality of life of future generations will suffer, he adds.

Professor Rapley's comments come in the first of a new series of environmental opinion pieces on the BBC News website entitled The Green Room.

"If we believe that the size of the human 'footprint' is a serious problem, and there is much evidence for this," he writes, "then a rational view would be that along with a raft of measures to reduce the footprint per person, the issue of population management must be addressed."

http://news.bbc.co.uk/2/hi/science/nature/4585920.stm


It's about time this issue got some M$M attention. Thanks to the fundie wackos it's almost impossible to discuss population control in a serious way anymore.

[Jamison]

1. It's an important issue!

"It's about time this issue got some M$M attention. Thanks to the fundie wackos it's almost impossible to discuss population control in a serious way anymore."

I so agree. If the fundies had their way, we'd have 12 billion here on this planet instead of 6 billion. They would say "Who cares if we don't have enough food to eat, water to drink, personal space, or shelter, it's our right to procreate like gerbils!"

[rmgarrette64]

19. It's also a very racist issue

Right now, the Western world is seeing a significant decline in birthrate. There is negative population growth already among Europeans, and people of European descent. So, calls for further population control are actually calls to control the birthrate of people of color.

Just something to keep in mind...

R. Garrett

[mike_c]

24. as an ecologist I disagree....

That's like saying that criticism of western developed nations-- largely of European descent-- for disproportionate resource use, or green house gas production, is racist. At some point we have to look beyond race and culture to acknowledge that there are simply too many humans for the Earth to support sustainably. I believe that we have already passed the long term carrying capacity of our environment, and that human population MUST be reduced. That means that people all over the world, regardless of race and culture, have to stop reproducing so damned much.

[lvx35]

33. Stepford wives...Its all about Stepford wives

beautiful barbie women that are robots..We kill too birds with one stone; reduce the population, and eliminate all the shallow guys! ;)

[AngryAmish]

43. Why not commit suicide?

Think globally, act locally. Maybe you could also kill your family.

[Matariki]

39. i've seen convincing studies that show

that high birth rates directly correspond to high infant mortality rates (due to poverty) and lack of education for girls. The issue of over-population therefore provides a very good vehicle for addressing the issue of inequity and poverty in places like you mention.

[depakid]

2. Overshoot.

Not a pretty concept.

Most knowledgeable people who've realistically studied the issue will tell you that human beings overshot the earth's carrying capacity some time ago, and as non-renewable energy resources go into decline, the proverbial chickens will be coming home to roost.

[Conservativesux]

3. Can anyone say " Soylent Green"?

[depakid]

4. Most people don't "get" the concept of exponential growth

Largely a consequence of innumeracy, I think-

Of course, that doesn't excuse the neoclassical economists who seem to believe in perpetual motion machines....

[tn-guy]

28. Contrary view from Tommy Smothers

I remember long ago when the Smothers Brothers show was on. During a routine about the population explosion Tommy Smothers took a contrary view:

"Look, I had two parents. And each of them had two parents, that's four grandparents. And everybody on earth had 8 great grandparents, and 16 great-grandparents. So instead of getting more people, the population should be shrinking!"

Sorry, I'm old enough now that I like to tell pointless stories.

[Uncle Joe]

13. I hear it taste just like chicken.

But seriously, this issue needs to be addressed front and center for the sake of humankind's survival.

Kicked and nominated.

:kick:

[rinsd]

16. I think Logan's Run would be more apt here (nt)

[Conservativesux]

31. Perhaps, but recall that only the Rich had the $$$ for such abodes.

This conclave was populated by the children of the wealthy.

[smirkymonkey]

5. It's about time this issue is being addressed.

Otherwise, Mother Nature is going to take care of it for us, and it won't be pretty.

[DoYouEverWonder]

6. Unfortunately, sickos like George Bush

love to watch people die and suffer. It seems they can never get enough.

[Conservativesux]

30. Exactly. Mother Nature does what she has has to do........

and like you say, it ain't pretty at all.

ZPG, like Yesterday !!!!!

Trimming the branches of the Human species.....or else !

[enigma000]

7. Overpopulation won't be a problem in Europe

With the birthrate far below the replacement level of 2.1 children per women, the population there will be declining for the foreseeable future.

[DoYouEverWonder]

8. Europeans know how to take the long view of things

and have limited growth in order to conserve their resources and sustain themselves. We would be much better off if we look to Europe for clues about how to sustain the rest of the planet.

[muriel_volestrangler]

9. That depends on the immigration rate

For instance, an academic study predicts the UK population in 2100 as 73 million - more than the 60 million now, because it assumes immigration will continue at the present rate from outside Europe.

And some might say Europe is already overpopulated - 115 people per square km in the EU, compared with 43 per sq. km for the world as a whole, and 32 per sq. km for the United States.

[Freddie Stubbs]

10. The US birthrate is fairly low also

It is immigration and the birthrate of immigrants that is fueling our growth.

[blindpig]

11. Sadly, it's not just the fundie wackos.

Libertarians reject population control as infringing on individual rights. Others fear the concept as cloaked racism. Religious like faith in technology solving all problem causes some to dismiss the problem.

We need to find just and humane means to deal with overpopulation lest the future resort to means unjust and inhumane. That and respect for the lifeforms that we share this planet with demands that overpopulation be addressed now.

[DELUSIONAL]

14. Some here at DU claim there is no problem

That the earth can support billions more.

Generally one of them will jump in and start throwing statistics to "prove" their -- not to worry about increasing population.

The major problem is drinking water -- eventually safe drinking water will become more expensive than oil -- or so some experts have projected.

The battle over land in the middle east -- is due to a combination of factors -- limited land, and limited safe drinking water (first thing the Jewish settlers do is cut off the drinking water to the Palestinians). Also the population increase is higher among the Palestinians.

The ocean used to be seen as an unlimited supplier of food -- but with the drift nets and dragging the bottom of every living creature -- many fishing stocks are crashing.

Yep I know I'm singing mostly to the choir.

[oregonindy]

12. zpg is the best.....

too many people on the planet.

[rinsd]

15. But what are the solutions?

And what paths will they lead to?

[K-W]

17. The solution is simple, but impossible.

The solution is having a secure educated population the world over.

Secure, educated people can make rational decisions about procreation. The problem is that so many people in the world make decisions about procreation based on thier cultures or religion, or economic factors.

[JudyM]

22. Right, and also there should be some limit, IMHO, on the number of

offspring a couple can have. I know a couple of families with more than 16 children. They can barely afford to raise them, and the planet certainly can't afford this type of, again IMHO, selfishness. In both these cases, directly related to the position of the Church on the topic of procreation and contraception. I have personally chosen not to have children solely because of the spectre of overpopulation... am considering adopting. The rules in China haven't played out well for female babies, but it seems that somehow taxing prolific parents is in order.

[wickerwoman]

27. I don't think a "One or Two Child Policy" is advisable.

At least from what I've seen in China. All the girls are crazy to marry Westerners so they can have more than one kid and most of those marriages end unhappily. And quite a few couples have kids "under the table" and pass them off as nieces or nephews. But then the kids can't go to school because they don't have paperwork and they end up thieves, beggars or in gangs.

But I think there's a lot that the government can do to reduce population without a number restriction starting with getting rid of tax incentives for having kids. Then, I'd say free education for the first two or three kids but after that, you have to start paying for the cost of educating them. If we were getting really creative, and again only as an alternative to a government limit on the number of children you could require couples for every child over three to adopt a "twin" for each kid they had. That way people could still have their mega-families without such a strain on the planet.

[Matariki]

40. or at least NOT giving them tax credits

for any children beyond 2

[CrispyQ]

48. Yes! And offer tax incentive for couples who have NO children!

There is a local couple who has quintuplets -- I believe they used fertility drugs. There was front page coverage when the babies were born & a write up almost every year on their birthday. They get tons of free stuff from corporations & local businesses. Sure it's expensive having 7 kids (they have 2 others!) but what about the single mother trying to make ends meet with her one or 2 children? No help for her, but we extol the couple that pops out 5 in one shot.

[mom cat]

18. Either we voluntarilly reduce our population or circumstances will

do it for us, and it won't be pretty.

[gulfcoastliberal]

20. K&R; More from article -

snip

Imagine organising the accommodation, feeding arrangements, schooling, employment, medical care, cultural activities and general infrastructure - transport, power, water, communications, waste disposal - for a number of people slightly larger than the population of the UK, and doing it each year, year on year for the foreseeable future.

Combined with ongoing economic growth, what will be the effect on our collective human "footprint"? Will the planet cope?

snip

Unless and until this changes, summits such as that in Montreal which address only part of the problem will be limited to at best very modest success, with the welfare and quality of life of future generations the ineluctable casualty.

http://news.bbc.co.uk/1/hi/sci/tech/4584572.stm

I'm not adding to the world's population burden. I'm so lucky to have a girlfriend who agrees with me! I'm a lucky guy.

[depakid]

23. That's INCORRECT

and it shows that the author doesn't get it.

What he's describing is linear growth. What we have is exponential growth. That's why it's described in terms of "doubling times."

Think of it like compound interest.

[muriel_volestrangler]

25. Wrong - world population growth is no longer exponential

It is slowing - here is the world population in millions, the yearly increase in millions, and the percentage increase - 1968 was the largest percentage increase, and even the absolute increase is becoming less each year now:

     Total inc %inc
1968 3,546  72 2.03
1978 4,287  73 1.69
1988 5,090  88 1.72
1998 5,914  79 1.34
1999 5,992  79 1.31
2000 6,071  78 1.29

source (with all years up to 2000, and projections after that)

[depakid]

29. It sure as hell is exponential!

The fact that the rate is decreasing, doesn't mean population growth is linear.

Take a look at the curve:



(Source: D. Meadows, 30 Year update to Limits to Growth, 2004)

Four possible scenarios arise from exponential population growth:




I don't want to bum anyone out, but based on current policies, scenario 4 is much more likely than scenario 3.

One of the better analyses as to why this is takes a slightly different economic and systems science approach, based on decreasing marginal returns:

http://en.wikipedia.org/wiki/Joseph_Tainter

[muriel_volestrangler]

34. And the last 2 points on that graph are apparently about 1960 and 2000

When you use such small amounts of data, you might think the growth is still exponential. That's why I gave the detailed figures, from a reliable source. The fact that the rate is decreasing means it is not exponential, by definition. Exponential increase has a steady rate of increase in percentage terms; exponential decay a steady rate of decrease. That book actually says "the curve is becoming less steep".

Of the 4 scenarios that book gives, only (a) is exponential. The others all show population growth increasing at first, then decreasing. The real world figures show we have now entered that phase.

[depakid]

36. Let's go back to the interest rate example

Interest is compounded based on original principal plus the additional accrued interest. Whether the interest rate is 5% or 1%, growth is still exponential.

It would be linear is a fixed amount was added every year- based only on the original principle. That's not what's going on- (although that's what the BBC author described).

Exponential growth is sort of a counter inuitive thing- that's why it's often expressed in population biology on terms of doubling times, as opposed to the standard linear equations like y = mx + b.

In addition, it's not very useful to look at figures in the aggregate. As one poster pointed out above, some northern countries may actually be in a period of somewhat stable or even declining growth- whereas many southern and third world countries have population doubling times between 20-30 years!

But that's deceptive, since northern countries- especially the United States, use (and waste) a tremendously disproportionate amount of resources. As some of these countries gain affluence and deplete resources due to outright stupid globalization policies, their impact (or to use Rees' term "ecological footprint) changes things dramtically with respect to that little dotted line on the graph that represents various ecosystems long term carrying capacities.

When that line crosses the population line- we've overshot. That's the defining issue.

[muriel_volestrangler]

38. Here's the definition or exponential growth

Growth at a constant rate of increase per unit of time; can be expressed as a constant fraction or exponent.

http://highered.mcgraw-hill.com/sites/0070294267/student_view0/glossary_e-l.html

So, if an interest rate is constant, then growth is exponential. The same applies to population growth - if the percentage increase each year is constant, then the growth is exponential. But the percentage increase each year has been declining since 1968. This has now got the the point where the absolute increase is now declining as well.

The point is that the doubling time of the human world population is getting longer and longer. In fact, just about all predictions are that it will never actually reach double the present level. It will follow one of the scenarios b, c or d from that book you showed figures from - none of which are exponential growth.

It's true that the author said the same increase will happen year after year, when in fact the increases are becoming slightly less each year - but just because it's not linear, that doesn't mean that it's exponential. It may turn out to be a damped sine wave, if you want it in graphical terms.

[depakid]

41. Too narrow a definition-

because in biology (unlike the analogy) rates of growth are rarely if ever constant.

Here's a more encompassing definition (that captures the concept) from the MIT group that runs the systems models on growth I cited:

"When some factor experiences exponential growth, the amount of increase rises from one periond to the next; it depends upon how much of the factor has already been accumulated."

The BBC author didn't say that the amount (raw numbers) added would increase or decrease. He went linearly (which may be nitpicking- but it belies a common misunderstanding of the dilemma).

The way it works with exponential growth is: the amount added- not neccessarily the rate- increases every year, whether at 1% or even .05% based on the sum of last year's midpoint population.

I would also add that this statement "In fact, just about all predictions are that it will never actually reach double the present level," is almost certainly true (in the aggregate) but maybe not for certain countries or geographic reasons. Why?

Because we not longer have the resources (particularly petroleum and natural gas) to continue producing food and other necessities on the scale that made this dramatic growth possible in the first place. Moreover, it's unlikely that we can even sustain the present population- much less any further incease.

[muriel_volestrangler]

44. And the amount of increase in world population is decreasing

so therefore it is not undergoing exponential growth. With exponential growth, the rate of increase stays the same; the raw amount of increase goes up each year, in exact proportion to the total amount already accumulated. Sorry to bang on about this, but I really want you to see that the world population is no longer undergoing exponential growth. Between 1999 and 2000, world population went up, but the amount addded went down.

So far, resources are rarely the reason for some countries not experiencing exponential growth in population. Developed countries, that can afford to buy resources, have seen a decrease in birth rates; and in general, as the GDP per capita in a country increases, indicating more resources available to each person, the birth rate decreases, by choice of the people, not necessity. Only in the ex-Soviet bloc countries has a decrease in resources seemed to lead to a decrease in the birth rate.

That doesn't mean that the future won't see a decrease in population growth, or an absolute decrease in population, associated with resource shortages, of course. I suppose you could say the deaths to due AIDS are already a sign of resource shortages (ie no AIDS drugs available)- it's a shortening in life expectancy that would show the resource problems.

[blindpig]

45. Still too little too late.

There's too many of us already so decreasing the rate of increase is a phyrric victory at best. The human race needs to reproduce at less than replacement rate for at least a couple of generations in order to reach carrying capacity. To be sure technology and social reorganization can help reach this goal but our numbers are by far the the largest factor.

That we might survive in a "Stand on Zanzibar" type scenerio is possible, but what kind of life would that be? And what of the myriad lifeforms that we share this planet with? We really need to get with the program in order to start taking the pressure off of the life on this planet of which we are but a part.

If the current trend you illustrate had started 30 years ago the need would not be nearly so pressing. It's heartbreaking that we dithered then and contiue to now.

[mike_c]

47. again, I disagree....

Exponential growth is:

dN/dt = rN

where N is the present population and r = b - d (for closed populations), b is the per capita birth rate, and d is the per capita mortality rate. At global scale the human population is closed, so no worries over the details of r, the intrinsic rate of growth.

If you have two populations:

dN_i/dt = r_iN_i and

dN_j/dt = r_jN_j

where r_i > r_j, both are still growing exponentially if r is positive, just at different rates. The same is true if i and j represent a single population measured at different times, with changing birth and death rates. In fact, this is the usual case for natural populations in exponential growth phases. The logistic growth model is simply exponential growth with a rate limiting term added to express limits to growth:

dN/dt = rN(1 - N/K)

where K is the equilibrium maximum population (often simplfied to the environmental carrying capacity). In any event, if the rate of population change is proportional to current population, population change is an exponential growth (or decline) function. I like to write it this way for my students:

dN/dt = {r(1 - N/K)} N

to illustrate that it's STILL exponential growth, but that the proportionality constant r is actually a proportionality function-- everything between the {} brackets-- rather than a constant.

This might sound like a technicality, but it illustrates the inherent capacity for exponential growth in all populations. I do not believe there is any evidence that the human population has ceased exponential growth, only that the rate of increase is currently less than its historic maxima. This is entirely consistent with the overshoot hypothesis. The real difference between scenario 3 and scenario 4 is what happens to K as a consequence of the overshoot. You might want to check out this link for an interesting paper about the concept of ecosystem hysteresis: http://cmbc.ucsd.edu/content/1/docs/scheffer2001.pdf. It gives a good explanation of why scenario 4 is likely.

edited to get all the HTML tags right....

[muriel_volestrangler]

49. Changing a constant to a function varying over time makes it all different

and stops it being exponential growth. Furthermore, population growth is declining not because of carrying capacity but because of choices of families, especially when they have contraception available. But that decrease in birth rates has mainly also been accompanied by an increase in resource usage per person. So simple modelling of human populations like other animal populations will not tell us much - a more sophisticated model is needed.

Just because a population has the capacity for exponential growth does not mean that it is experiencing exponential growth. The evidence is in the figures I gave - and the fact that the rate of increase is less than its maximum (and has been for over 30 years)is actually quite important. You can't just redefine 'exponential growth' to mean whatever you want it to.

[mike_c]

50. I'm sorry, but we'll just have to agree to disagree....

The exponential growth model is ALREADY defined by a FUNCTION of proportionality that varies over time-- the constant r is simply a notational convenience-- because r = b - d, so dN/dt = rN is exactly equivalent to dN/dt = (b - d)N. Birth and death rates vary both stochastically and in response to environmental variation. Another way of saying this is that real populations NEVER have constant intrisic rates of change.

Likewise, we can define:

a = r(1-N/K) = (b-d)(1-N/K)

and the logistic growth model becomes:

dN/dt = aN

i.e. exponential growth with a density dependent self limitation function under the hood. Once again, all we've done is employ a notational convenience. Just look at the sigmoid shape of a logistic population growth curve-- it's comprised of an exponential growth phase followed by an exponential decline in the growth rate (ignoring, for the moment, its potential for deterministic chaos behavior).

As for K, the term "carrying capacity" is unfortunate-- K is best thought of simply as the maximum equilibrium population. That can be the result of environmental limitations, disease, etc, but it can also be the result of self-regulation, although such conscious self-regulation-- deliberate abdication of reproductive opportunities-- is exceedingly rare in nature. Even among humans the normal biological way to achieve this-- celibacy-- is regarded as abnormal behavior. The few non-human instances that occur naturally offer compensatory benefits like inclusive fitness (and still don't actually limit population growth in most instances-- they just influence WHO reproduces).

[bleedingheart]

21. Global pandemics can reduce the world population pretty quickly

aside from that...perhaps there should be more programs to promote voluntary sterilization?

What are the real solutions to this problem?

[Miss Chybil]

26. You're on the money. The earth will cleanse itself - probably soon. nt

[Conservativesux]

32. Answer: Cheap Male Birth Control sans condoms.

The fact is that condoms DO inhibit the pleasure for Men during sex and that IS a hinderance to the goal of population reduction .

And condoms break/tear and allow sperm to get loose, too.

[DoYouEverWonder]

35. Education and attitude is half the battle

and I think we can reduce population growth without resorting to draconian measures. For example, I remember reading about a study they did in India back in the 70's(?). They were looking at ways to reduce the birth rate, so they went into a number of towns that didn't have much in the way of entertainment. They built movie theaters in these towns and the birth rates were reduced substantially. This is just one example, but creative solutions combined with good sex education and affordable and accessible birth control will go a long way before we have to go the way of China to reduce population growth.

[Triana]

37. The Population Connection has been...

...advocating population control for decades. No one listens, least of all the fundie gov't of the U.S. I notice this on the BBC - not on CNN or Fauz Newz or MSNBC. When will THEY report on this as a core issue of concern to all of humanity?

Pollution, poverty, global warming, -- at their core, all are a result of overpopulation. While we can do things to reduce pollution and poverty (we usually do not though) -- we still have too many people inhabiting this planet and these problems will continue progressively until the population is brought down to a sustainable level.

That is the crux of the problem. But NO ONE, least of all the breeding fundies, want to talk about THAT.

[wuushew]

42. kick

:kick:

[mitchum]

46. I have a friend who left the Sierra Club over their unwillingness to...

address this issue.
It is INDEED a factor.