While many large families live off of the government, many do not. Many are self-sufficient, responsible people raising self-sufficient, responsible children. Calling 3-or-more-children families (which I certainly do not consider a large family!) "eco-criminals" is simply ludicrous.

Alexandra, New Mexico, USA

Wow people just listen..sure it would be great to have a big family would be great but its ruining and over populating our planet. I do frown when i see families(especially young) with like 5kids and the granparents are stil lalive. Its wrong women need to stop giving in to their estrogen and think

Ashton , coram, USA

Big families are beautiful, all those people who love each other and would do anything to protect one another. would be nice having 11 brothers and sisters to look for advice and enjoy life with. If only the world treated each other like this maybe people wouldnt need big families. shame!

martyn, newcastle, uk

It disturbs me that there is such a lack of awareness and consideration for humanity and the environment when it comes to people having large families. Having a large family is a selfish and irresponsible act that needs to cease in order for our world to start recovering from its problems.

Lindsay, Chandler, USA

my husband and I moved here to CAnada. He is working and giving to the economy. I have five children. They are clean, loved and I spend quaility time with them. my toilets are clean, joy in my home and no extra cars or trips by air making pollution. Selfish people wanting more for them. our there!

Tracy, sherwood park, canada

We are heading for a population crash, be it through runaway climate change, peak oil or global resource wars. Anyone who knows anything about the environment will know that we passed sustainability in 1985 when the world population reached 5 billion. By 2050 there will be 9.2 billion people here.

david Jordan, Preston, UK

I have ten children. To be honest with you. The world doesn't care for the enviroment. With all those factories that pollute the air what diffrence does it make if society has a lot of children.

Reagan, Abbey,

I personally think it is of no one elses business how many children a couple have. I am pregnant with my fifth child and i can tell you as a mom of a large family we appreciate the value of a dollar, the saving of energy and are way less wasteful than people that only think of there selves.

Heather, london , Canada

An (adult) child from a large family of 8 offspring I wish to air my view. Parents should think before they go off and reproduce- think of the future of their children. Too many parents think it is enough to just cloth and feed their children and neglect their emotional needs.
I am not reproducing

Maeve, Dublin,

mum of 4, grow own veggies, home educators & can survive without electricity, gas etc because we are survivalists. Been green since it was a freaky thing to be six people one car compared to those who go to work alone. the response to propaganda that PEOPLE breathe - horror of the selfish community

Diana Atkinson, Altrincham,

Amused by one poster's suggestion that his children should be able to opt out of funding health care for the elderly child-free. Who does he imagine is funding his children's education, health care and tax credits for 16+ years of their lives? Do I get an opt out clause on those payments, too?

J Bright, London, UK

People who have more than two children should be sterilised. When people/other countries criticize China for having a one child policy then they should look at their own countries problems before they go mouthing off. At least China is doing something to control their population. People who keep on breeding like rabbits should belong to the “Rabbit Club”. Up the local council estate where I live there is a couple who five children and the whole family live off benefits because they can not be bothered to get off their rear end and get a job. Why should the taxpayers keep people like that?

Claire, Hull, UK

We are a virus growing on the body known as earth, when we breed to the extent that the body can no longer sustain us then we will kill it and ourselves in the process.
A beautiful large house will have room for a pre determined amount of people, if you over fill it it will become a slum.
Less people on the planet means everything will last far longer, no fuel or energy shortage, no famines, great medical care etc, why is this so hard to understand ?
Lets stop being so selfish and greedy and begin to appreciate what we have.
Ian, UK

Ian, london, uk

Having more than 2 or 3 children in the 21st century is not only irresponsible but quite possibly criminally negligent. Apparently some people will never realize that the planet simply cannot sustain unlimited numbers of humans. Even if we successfully destroy all wildlife, there will not be enough food or water or oxygen to sustain us. This is a common sense issue. It is probably already too late, but alot of people need to wake up. Do some research. Study the history. If you are wrapped up in a religious extremist view then you are probably looking forward to an apocalyptic end to humanity. I feel sorry for those types. But, if you have any compassion at all, you need to understand that we have finite living space and resources, and that we are part of an ecosystem that cannot survive without all - or most - of its components intact. Have pity on the children of the future.

James, Jacksonville, Texas

i have 7 children, larger families are not a "crime"
we buy in bulk, we spend less than most families with 2 or 3 kids that just waste. No one has the right to say how many kids a woman should have, it is personal choice!!!

jean, nsw, australia

humans today are run on greed i have 6 children i work and suport my family . how can people think that large means a crime. wen the crime in our world is the few big cats . the money greed people who destroy this plant for there gains. i could give hundreds of examples of goods movements ect all pointless . just make the scales ballance . but maybe the large family is wrong and we should all conform and live in small boxes we then would be easer to control. mr g wilson

gary , durham, was called great britain

Mary had her figures so wrong, the US population is less than 1/20 or 5% of the planets population and use 80% of the worlds resources

russ, limassol, cyprus

I think that how much money a family has has more to do with how much pollution they make then how many members there are of that family. That's why the US has only 1/5 the worlds population, and uses 30% of the world's resources. There aren't too many of us, we're just using more than our fair share.

Who pollutes more? My family of 6 who can't afford to take plane trips and has to economize? Or a married couple without children, who makes a good living, and goes on vacation, out to eat, etc,etc..

Mary, Minneapolis, MN

Excellent article and would recommend readers to visit the Optimum Population Trust website. We have a finite earth with finite resources and finite time. An ever growing population is the biggest issue facing the earth and all her people. How many people are living in total and absolute poverty today. Their day to day misery is beyond the comprehension of most of us. How will more people solve this issue?? I would ask those who believe in a God to use a little more meditation and prayer rather than just faith. There was a time when we had to breed continuously in order to survive such was infant mortality combined with wars, plagues and famines. The planet belongs to us all - not just the God-fearing, not just the rich, not just those of us alive today but hopefully also to generations of our unborn descendents as well. We need to treat their futures with some respect and give them some hope of inheriting a planet worth being born on to.

Stephen, Lancashire, UK

the main factor driving the world population explosion is the availability of (relatively) cheap fossil fuels like oil.

someone even said 'modern agriculture is just a way of using land to turn oil into food'.

it's hard to imagine the 8-9 bilion people projected to be on the planet when oil finally runs out finding 'sustainable' alternatives.

ned sheffield u.k.

edwin debes, sheffield, U.K.

Actually raising more children in one family is much more efficient. Six people can sit under one light bulb as well as 3. My 5 children and I can ride together in our own carpool. We buy in bulk, recycle by using the same clothing and equipment and even shoes over and over again and share rooms, electricity, heat, a/c. Having 5 children is not the same environmentally as 5 couples having one child each and needing to house, clothe and feed each one individually. Children who grow up in large families have to think about the needs of other, not just themselves and have no illusions about the world revolving around them. They can be taught to walk softly upon the earth. In the end, those with few or no children sould appreciate us "breeders". Our kids will be paying their Social Security some day.

Tess Schreiner Foster, Fairfield , USA

The earth is a limited resource, therefore population will be limited, one way or another.

Many people here seem to be saying 'I can have as many children as god grants me'. This means they either do not know what the 'tragedy of the commons' is, or they can not comprehend it, or they do not care.

At least if its the latter they may be able to make the best of a bad world.

Personally I'll have no kids and guilt free flights, cheers!

Matt Prince, Exeter, UK

I couldn't agree more with both sides however for some of us parents who support our own large families,are not on government grattuities or assistance it is my right and God's right to choose how many children i want to have. In addition if people would slow down and drive speed limit we would not pollute the air as much as we do. Also here you have families with 1 or 2 children who neglect them worst than a loving mother or father of 5 or 6 children. You are no one to say what is best why don't you go home and dump your bottles of aerosol hairspray, stop smoking and slow down on the freeway see how much more you could help the environment.

cj, houston, tx

It is long past time the press started treating these odious eco-freaks with the contempt they deserve and ignoring their nasty little pronouncements completely. Deny them the oxygen of publicity and we can all go back to enjoying life instead of putting up with this constant barrage of anti-human propaganda.

Chris, Birmingham,

Eileen McCloy's comments are amusing. How easy it is for greens to criticise frequent flyers and four wheel drive owners but when the criticism comes back to them and their large families doesn't the story change? Population is the elephant in the room when it comes to planetary despoilation. Fortunately the CO2 induced global warming myth is a lie so no problems there but excess people mean overuse of resources and more waste.

Ian, London, UK

I couldn't agree more. I'm rather sick of parents who have made the lifestyle choice to have children whinging about whether I drive a 2 litre or 2.8 litre car or how many driven wheels it has when their kids will produce many million more tonnes of CO2 than my car could ever produce. If you choose to have kids you cannot legitimately complain about the lifestyle choices of others to fly or drive.

Dave Russell, Horsham,

Oh, forgot to say ... hte notion of having large families to support you in your old age should be left in the Third World.

Ian, London, UK

It's short sighted to compare the footprints of large families and small ones when they are small. They all grow up and have families too (the rabbit factor). All artificial conception should be banned as no woman has a God given right to childbirth; there are enough poor kids out there who need adoption. I speak as an IVF Grandad who loves his grandkids dearly, but it is stupid to think they, in their own right are not already and certainly will be, an artificial drain on resources.
But the debate is all wrong, man can never 'save the planet' how he likes it; we are too puny so lets stop looking at how the other lives and enjoy it while we can.

Keith Peat, Sutton on Sea,

6 children in one family produce far less CO2 emmissions than 3 familes each with 2 children... Take a look at our 4-6 rubblish bags each week and then look at next doors two bags for only two people (no children).

Ever tried taking 6 children on an Aircraft flight? No - neither have I (little expensive) we instead choose to holiday locally in the UK camping or other low CO2 methods.

As it stands the UK already has only 1.7 births per lifetime per female and that includes children from those settling here from overseas.

As usaual it is all about twisting statistics to suit your own ideas - stand back and look at it globally and you see a world dying for lack of strong family units that are safe for children to grow up in.

Anyway another generation and reports like this won't exist as we will have reached crisis under-population.

Andrew Haley, Cheltenham, UK

when i've read the article regarding restriction of having to many family members i said that's absurd...i think the problem of the world does not fall on the population of human beings ( the world is too big and people just come and go) but wrong and unpleasant attitude that he/she has with his/her environment (the nature and the people around him).
let people multiply as long as they can feed them send them in school and teach them the good family values and behave a true human being the way GOD want us to behave.
anyway people have different views others i'm sure agree with having small family or stay single at all..
" live and let live!!!!"......there are so many problems in this world we have to tackle and resolve not only the population....
if only man knows how to care so we can all all live peacefully....

GIGI Gorospe, Makati City, Philippines

The earth was made for man, not man for the earth. Of course we would take care of the Earth, but restricting all the life that would inhabit is missing the purpose of the world. The world is about families and happiness. This is actually a bigger issue than Ms. Templeton might assume. It is not about what is reasonable, it is about what is right.

Erin, Naperville, IL

I happened upon this article and agree with the think tank. I have two children. I think perhaps I could have had three. But, more than that and I would feel disgusted with myself for not caring more about the earth and others, only myself. For the woman, Eilenn McCoy, from Glasgow, she stated that she needed offspring to care for her as she aged!? So, by that reasoning each of her 10 will in turn need 10 of their own for their care in their twilight years and so on....reminds me of mice! It's always people who have let out a pile of kids who are most defensive. Really! Did Eileen need farm hands? God also instructs us to care for ourselves and the earth. The, "be fruitful and multiply", excuse so resorted to was a command given when things were quite different. In Bible times the world was relatively unpopulated presumably. Ah! Paradise!

Sylvia Anderson, Vancouver,

I think that the mam of "Professor" Guillebaud is the most important responsible of the world pollution caused by the poor intelligence of her children, in comparison with me that I am mother of six beautiful children!!!!!

Lucia, pisa, italy

Japan is beginning a quiet collapse because of the population shifting from young to an unsustainable top heavy older mean average age. Here in America the 'basketball' population of baby boomers is about to come out the 'garden hose' of the work force, all with hands out for their retirement benefits, only to find not enough young exist to work and sustain them. The technology develpments and efficiency efforts along with legislation in developed nations are working well to reduce "greenhouse gasses" and are in fact outpacing the power grabbing efforts of the Greenies. The exact opposite of your shallow article is true. The world needs large families for stability, to sustain and contribute to the older population. Enormous progress continues to be made in the energy industry to reduce heat output per capita and reduce wastes...Let's trust God with the size of our families and cast off limitations! He created the world, commanded us to be fruitful and multiply; God sustains!

mike woelfel, houston , USA/ Texas

As a father of 7 children I do not agree with this view.
All you have to do is pause a little bit in order to ponder about the most important things in life and about the purpose of life itself. You will find the answer right in your heart. Deep in your heart.
Having children, even many children if this is your desire, is a blessing from Heaven. It certainly takes courage, hard work and will to sacrifice. But it pays such joy that cannot simply be written on a blog on the internet. If all people would follow your advice, what would be left?
Large families are not the problems of humanity. It is the selfishness of those who spend their lives in an effort to acquiring riches, success and comfort, avoiding the sacrifice and the responsibility of a life centered upon helping and teaching others. Any other path will lead single people and humanity as a whole to great sorrows and eventually to self-destruction.

Gianpaolo Debiasi, Bolzano, Italy

I agee that you are VERY wrong! Children are a blessing and there are many, many ways to take care of our environment than limiting the size of our families. Children are a blessing from God.

Jennifer, Austin, Texas

This assumes that every child born today won't have a fear of flying and will fly to New York and back 10 times a year. Such is to be expected from an arrogant emeritus professor. Maybe if there was a decent health system, there would be no need for citizens to create offspring to care for them as the elderly. And who wants the remit of their birth to be a slave to their parent ? As always remove the need, and the burdens of parenthood will reduce the incentives of procreation, reducing population effectively and with choice. This nonsense is the new carnation of 21st century socialist communism that is obsessed with CO2 emissions, and the perverted science that associates its biological role. Yes, resources become stretched with greater populations, but civilizations only evolve to succeed with sustainability and natural social cohesion. It's becoming increasingly divided with the proletariat and the bourgeous. Less of the fascist totalitarianism please. More democracy.

Lionel Tiger, Birmingham,

You are in wrong!!!

Andrea, Ascoli Piceno, Italy

Hopefully in the future people will live a carbon neutral lifestyle.
If so Mr. Guillebaud is wrong.
Family planning is unlikely to play any significant part in solving the problem of climate change. Funding for esoteric research into family planning should be cut and the savings redirected to research into real solutions to global climate change.

nsleigh, launceston, australia

Drivel like this from dupes like Mr. Guillebaud is why the UK and the rest of the West are declining.

Wake up people, the birthrate in most of the world is already below the "replacement level" of 2.1 per woman. Why does population continue to skyrocket? Because death rates have fallen dramatically. It's NOT that we are "breeding like rabbits", because we aren't, it's because we are no longer dying like flies.

Meanwhile, there is one glaring exception to this below replacement level birthrate trend, and that culture is one that doesn't care one whit about the environment, enslaves women, and persecutes and murders homosexuals. And it's taking over Europe even while dupes like Mr. Guillebaud continue to spout their nonsense.

It's enough to make one wonder if the eco-fiends are in cahoots with the Islamic fascists. Do the Wahabbis fund the global warming hoaxers? Someone ought to check.

Nick Byram, Sacramento, CA, USA

What about your carbon dioxide emissions to say this?
Children are gifts more than life!

Antonello, Bolzano, ITALIA

I'd like highlight three possibilities to explain this speech:
1) Mr. John Guillebaud was born by a test-tube, since he doesn't know what family means.
2) Mr. John Guillebaud is a only child, since he doesn't know what brother means.
3) Mr. John Guillebaud is an emeritus professor not because of his worship but somebody else, since he doesn't know anything.
Who doesn't know, he will teach.
An happy husband and daddy of 4 Co2 producers

Paolo Brotto, Milano, North Italy

John Guillebaud, youd'better begin to make earth air better going to Mars saing such fooleries!
Gianmario, 8 son's proud father.

Gianma, Verona, Italy

It's very stupid and incredible..
+ family!!!!!!!!!!

+ life!!!!!!!!!!

Nicolò A.N.F.N., Milano, Italy

Dismay. That is the emotion I feel when I read the responses of people who belittle the notion of having fewer children. If we do not control our population through free choice, then it will be controlled for us. There is no escaping it. Do we want to get together and of our own free will decide to limit our population for the good of our children, their children and this planet or do we decide not to and drift towards massive destruction due to famine, disease and war?

peter, Wellington, New Zealand

Emeritus professorJohn Guillebaud :
a family of six component, doesn't produce pollution as so much six " single ".

ADRIANO ZANASI, Ass. ANFN, BOLOGNA, ITALY

Emeritus John Guillebaud, professor of ""family planning"":
a family of six components doesn't produce pollution as so much six " Single".
Adriano four childrens father's.
Member of A.N.F.N.
Italy

ADRIANO60, BOLOGNA, ITALY

As light speed is faster than sound speed it should be for this reason that people seem to be brilliant 'till open the mouth (and sais these opinions)

Pino, Genoa, Italy

This article had me chuckling, and to take it seriously is a little too much. OF COURSE less people=less pollution. How could anyone argue with that? What isn't being taken into account, however, is Free Will: to live our lives as we feel called to. To assume that just because something makes sense on paper it will automatically transfer well to a real-world scenario is ridiculous. I would no more stop having children because it's a government mandate than I would wear a seat belt for the same reason. The world has a better chance of getting big business to regulate their output, getting chemical-free products into each and every home, and of promoting solar and wind power than it does instituting population control. The ramifications of those things are positive, controlled and doable. The consequences of global population control are scary, and we have only to look to China for a real-world scenario. It will lessen us as human beings and weaken our society to live w/o free will.

Shani, Phoenix, Arizona

I've got a better idea. Let's have people like Sarah-Kate Templeton and her eco-extremist cohorts narrow themselves down to zero children. That way the problem with the environment will go away with them in about 30 years. Fact - there is no problem with the environment. The sun is getting hotter. So tell me then how we are responsible for making the sun hotter? Perhaps it is all the hot air being thrown around by eco-extremists. How do you explain the fact that 1000 years ago there used to be grape vineyards in Greenland? Did our carbon output a thousand years ago plunge our planet into a minor ice age? So, how do you account for the fact that people like Al Gore want us to change, but have no plans to change themselves? Perhaps if Al didn't fly in his personal jet every other day, or turn the temperature down in his 10,000 square foot humble home he might make a differece. I, for one, have four children and plan on having more. I couldn't see a day without any of my kids.

Matt, Boones Mill, VA

John Guillebaud, youd'better begin to make earth air better going to Mars saing such fooleries!

Gianma, Verona, Italy

Whatever ones views on the theology of manmade global warming, it is an inscapable correlation that pollution of all forms and potential damage to the planet is directly proportional to population.

More people pollute more, use and waste more energy and more resources.

The Bible and Koran state their god's (evil?) command to "Be fruitful and Multiply" - Been there, done that, got the T-shirt.

Brian Vallance, LEFKIMMI, Greece

The Bill and Melinda Gates Foundation, the WHO, UNESCO, USAid, Save the Children, Oxfam, etc, all try and save lives in communities that cannot sustain themselves. Perhaps these are the organisations that should be considered a threat to the environment. How does a community that cannot sustain itself have more right to life than one that can?

Joe, Cape Town,

I have no children, so can I feel guilt free about making 1,200 trips a year between London and New York?

Taki, Retreat,

One reader wrote: "There is clearly enough room on the planet, enough resources too. " That may be true if one thinks it doesn't matter if other species vanish. Many animal, bird, fish, and plant species are going extinct because humans are crowding them out , over-consuming them, or altering habitat too fast for them to adapt. Personally, I think people should be taxed for every child other than the first one or two they bring into the world, not get deductions.

BJ, Madison WI,

A home schooler about 10 years ago did a mathematical test and discovered that all the people in the world could fit in the state of Texas, with about 6 square feet around them. That would mean the rest of the planet would be have no people on it. There is clearly enough room on the planet, enough resources too. Why does man continually want to enslave others? It's just in our nature.

Ryan, Irvine, CA, USA

why are people so angry. it's a really interesting suggestion. no one's saying we should force people to have fewer kids, just that we might wanna think about environmental consequences when starting a family. i'm from a fairly big family myself (i have 4 brothers) and i love it. would i want to have a large family of my own? Well the population issue would make me think twice - adoption of additional children might be an interesting option.

yes, the population in europe is declining, but i don't have a problem with immigrants 'flooding' in - sometimes when people talk about that i feel that they're actually saying - 'let's keep Britain white' or 'i don't want to have to compete for jobs'. As for the developing world - even with their exploding populations, they still, in general, emit less co2 than the west. therefore it's up to the west to make the bigger reduction in co2 even if it means a reduction in living standards (we should try anyway)

Nicola, cambridge,

Two words in regards to the above... Enviro "MENTALISTS''

John Boyle, Newcastle, UK

You know I believe there is already a law like this. Guess what, it's in China!

Richard, Brownsville, Texas

We've heard this before, Paul Erlich, The Population Bomb, none of his predictions came true did they. We've heard this all before, Thomas Malthus, none of his predictions came true. Whatever choice a family makes about their family size needs to be their choice. To do otherwise is to violate the law of subsidiarity. We are expecting our eleventh child and I would say we are the most resource efficient family in our neighborhood. Our trash production is the same as everyone else on the block (all have fewer children), we put more people per square foot in our house. It costs just as must to heat and cool the 3000 square foot house in which my family of 13 resides as does the house with a family of 4. Let's not forget people are the ultimate resource.

Matt, Elkton, MD, USA

Maybe John Guillebaud and Al Gore should strip naked and sit in an open field until they dissolve into the earth. Then I would know they are truly committed to their cause and not just (do as I say, not as I do), agents on the loose working to shame me into altering my lifestyle or buying their carbon credits from Mexico and China, while they jet around the world dumping a billion more carbon footprints in one trip that my family will in a life time.

Lead by example please

Ken C., Chandler, AZ

We don't need children to pay for our care because we should plan ahead & pay for it ourselves. Actually, those of us who work already do pay, because we hand over 11% of our earnings every month. Of course, a large portion of that money is spent on children. In fact, childless people have to subsidise the free healthcare enjoyed by other people's children, plus pay for their education & all the other perks they enjoy. Having a lot of children is greedy, selfish and arrogant. It increases the tax burden on other people, contributes massively to overcrowding and exhausts the planet's natural resources.

Carol, Derby,

Professor Guillebod is making a valid point. The planet's population is growing at an alarming rate. When Neil Armstrong walked on the moon in 1969 it was around 3 billion. In 2000 it was 6 billion. In 2005 it was 6.5 billion and is projected to be 9 billion by 2050. Use of the planet's resources cannot be maintained sustainably (which really means make them last a bit longer, since many of the resources we use cannot be easily replaced) unless the population falls. A sustainable number for human population is around 1 billion according to some studies. If we can't control our numbers, then Mother Earth certainly will as famines, water shortages, energy shortages and the rest take their toll in terms of war and pestilence. The average life span of a species is one million years. Humans are already on borrowed time.

Bob H, Glasgow, UK

If we are to have any real effect on population growth we should start in the third world where a family might have 15 children just to be sure that someone is around to take care of the family farm. How is this "sustainable?" As these exploding populations enter their own industrial revolutions the effect on the global climate will be staggering. So you lefties think that just because you are poor you have no impact on the environment? Poor people have to eat too!! Who out there is suggesting birth control for Africa?? Think of all the new cars being put on the road in China! Let me put it this way - if America and everyone in it disappeared off the planet tomorrow, there would be no difference - it would just take Mexico a few years to catch up.

jonny migliore, tucson, AZ, USA

There is one way and one way only that this sort of process will work - and that is in a closed system. No more financial migrants and everyone already legally here operates by the same rule. No exceptions whether you rent a council house or own Buckingham palace, and no more financial incentives for the terminally workshy for squeezing out innumerable Kylies and Jasons.

Dan, Hampton, UK

Enough Already! Perhaps all of you CO2 alarmists could do the world a favor and instead of trying to force others how live and reproduce you could step up and reduce emissions by eliminating your industialized-disproporionally-consuming-self.

Stuart, Humboldt, CA

Is the Optimum Population Trust a front for the Chinese Population Bureau? They seem to exist in the same moral, illiberal vacuum.

James, York, UK

This is another reason why having a personal carbon allowance would be a good thing. Everytime I drive my car it is full of 5 people. Can a single person stake the same claim ? As a family I think our total CO2 emissions are equal or less than a couple earning the same amount. When our house is heated there are 5 people in it, not two. An average UK couple same age same earnings probably take more short / long haul flights, which is the fastest way to bump up your co2 emissions. Would they recycle, source local food or grow it, not buy new /share/freecycle /ebay...?etc It's not about how many of us there are on the planet but how we live - this is soooo key. Politicians don't know how to tell us but we have to not consume so rampantly...but our economy allows us to. Developing countries need better sex education and political rights for women, it's the ONLY proven way to bring down birth rate. Whatever the UK birthrate this year or next - it will not change our nations CO2 output.

emma, suffolk, uk

We need to cut the number of British born children because we need to make room for all the immigrants the Labour government insists we need for 'the economy'.

Kevin Smith, London, England

Once again, people are using misinformation to lead to even more ludicris solutions. There is no connection between carbon emissions and planet warming, from 1940 to 1980 the global temperature steadily dropped, at a time when car ownership quadrupled after WWII, and energy consumption and population growth soared through the roof in the US and around the world. Earth has been through over 7 ice ages without the help of man, and even now we know from NASA that temperatures on jupiter, mars and pluto are also experiencing increasing temperatures along with Earth, so whats the common link there? the Sun maybe?

In any case even if the leftists are right then they should follow their own logic and go back to 7th grade science where we all learned that plant life flourishes when CO2 levels are higher, and historically rising civilizations are generally marked by rising temperatures because crops grow better in warmer climates. so hurrah for big families

jim, pacifica, CA

Now, how his it possible that there are still people that believes that "man has no influence in the earth climate"...how stupid can you get ???
I don't believe that climate change is a drive strong enough for birth control (economics are and you see that all over develloped countries, just look at western europe birth rates) so I think that we should all focus on dumping fossil fuel ASAP and make the technological transition to renewable sources of energie. Our governments and industries can make that economical viable and that's the anwser, not birth control.

Jorge Goncalves, Lisbon, Portugal

There's only so much...space, water, air--nothing is limitless. It doesn't take a genius to figure it out, especially in this day of rampant environmentally caused cancer, decaying and crumbling infrastructure and hideous overcrowding. Does the whole country have to look like inner-city Newark before people will begin to suss it out? I certainly don't want to live with three families above me, three below and not a small green patch to call my own. It calls to mind those movies which try to evoke a vision of the future by showing the entire planet as one uninterrupted city. Has anyone ever seen THX-1138? It's unconscionable.

F. John Becker, New Jersey, USA

The good news is as the native UK culture continues not to reproduce and they offset the loss off workers with 3rd world labor soon the UK will itself become a 3rd world country with complete loss of cultural identity and polarization of its subcultures (which will lead to ethic violence and the population reduction your are looking for!). So good news as you slide into the 3rd world (much sooner than you think) and your disposable incomes vanish, you will in turn have a smaller carbon foot print! So enjoy the slide down the toilet into a greener 3rd world lifestyle!

Greg, Rio Rico , Arizona USA

What kind of world would it be if men and women having children is considered a crime against nature. Whoever supports this clearly has some other agenda be it the homosexual, abortion and what not. Let us have our children!! Come on really? I will save the carbon debate for later but my overall point is there should never come a day when men and women that love each other and having children the NATURAL WAY should be considered unnatural

Joshua Porter, nashville, USA, TN

When one looks how the British have uncritically accepted Labour's surveillance society, how they have meekly lain themselves down to be trampled by the global warming stampede, and then tripe like this, one is inclined to think that the bureaucracy must be drugging the water over there these days.

John Miller, Foster city , CA, USA

We have 7 children, the greatest blessing(s) of our life, all are being raised as conservative Christains by the same parents (a Mother and Father) and will be private gun owners. Thank God in heaven for our liberty! If this destroys the enviorment, I'm glad to do my part. The author seems to be quoting from the communist manifesto. Hasn't that system already proven to be a failure?

Chris, Yelm , Washington

The fewer children we have, the fewer there are to pay for our medical care when we are old. Furthermore, perhaps my children should not be forced to pay for your medical care if you have no children. But perhaps this won't be a problem after all. I am sure there are those who will only be too happy to reduce co2 emissions by helping a few of the elderly to die a little bit before their time.

J. Scarinci, Franklin Square, USA

I'm a 37 year old father and my wife is 32, we have 2 kids and we want to have 1 or 2 more. Try to stop us!!

Joe, san francisco,

Is there no end to the Stalinist mental enviros. Apparently not!. Do they they let facts get is the way of their insane diatribes? Apparently not! Here's a few facts. Carbon Dioxide is essential for life on earth.... Carbon Dioxide is NOT a pollutant..... Carbon dioxide produced by mankind is a very small percentage of that produced naturally.... There is ZERO evidence than man made CO2 has any affect on the climate....

Jack Bauer, London, England

Why is it so wrong to think about the future when planning one's family? Nobody is being asked to murder any existing people, nor is this related to eugenics in any way. It's an issue of resources--they aren't infinite. Uncontrolled growth can't continue.

The fact is the fewer children you have, the better chance they have of a better life. I look forward to the day when people congratulate me on deciding not to have children rather than ask me what is wrong with me. The children I didn't have aren't upset about it, I promise. And there is more room for your children -- and animals, and plants -- because I did not have them.

So some people still have a dozen or more...that is their foolish choice. It doesn't mean those of us who still have the option can't rein in our pride and realise that our own DNA isn't really that special. Stop leaving environmental problems for future generations to solve, when we can do something NOW!

LW Jolly, Reading, Berkshire, United Kingdom

Here's an idea, when genocide occurs in Africa, a country with the highest growth rate of any country, let it happen. In fact, accelerate the process. All developed countries should reject immigration of people from third world countries that don't limit birth rates and have an exponential growth rate, ie India, Indonesion, Pakistan, Bangladesh, all of southeast Asia, Africa, etc. Instead of sending food and medicine to third world countries, give them contraceptives.

Phil Miller, Springfield, USA

Micael FW is getting things rather confused I think. Eugenics is what we are practising now in the form of selected embryo implantation to circumvent inherited diseases. What is being proposed is that the world should voluntarily limit its population. Not a likely scenario I grant you.

As for what can sustained ask any ecologist (i.e. professional scientist as opposed to 'greenie') and you will get a shrug of the shoulders. No one really knows how many people can live on the earth in harmony with their surroundings - maybe it's zero!

We must also remember the Judeo-Christian-Islamic philosophy is built upon the principle that nature is there to be exploited by people.

When combined with the powerful drive that each of us has to procreate and thus propagate our genes. I am inclined to my son's point of view. Perhaps we should all just carry on and cause the extinction of ourselves and many other species.

You can be sure of one thing though the insects would survive.

Tim A, Bournemouth,

I see no hidden eugenics or Soylent Green ideas in this simple statement: We can replace but must not grow our population. If you want to have 10 children now, you're condemning some future family from having even 2 if Earth has shot past its sustainable population and must begin to shrink. Having more than 2 children is a greedy and short-sighted grab at the resources of the future to enjoy them today.

It is an entirely reasonable and conservative principle to build sustainable cultures, systems, and population densities, and I welcome this paper's stimulus to discussion.

J2, Oklahoma City, OK

Global warming is a symptom. Population growth is the disease.

Had population grown at the current rate for the last 2000 years, there would now be 50,000 people per square foot of land in the world.

Figure it up!

John A. Broussard, Kamuela, Hawaii

So typically leftist and arrogant. Maybe these people who suggest such totalitarian idiocies ought to start with their own extended families and save the rest of us the trouble. The left used to whine about "FOR THE CHILDREN", now they're blaming families who have " THE CHILDREN"!

I guess that makes communist China the most moral nation on the planet since it mandates how many children the hoi polloi can have. Like I said, so typically leftist.

Hankmeister, Urbana, USA/IL

As the proud father of nine children, I say "Balderdash!" to this poppycock. If reduction of carbon emmisions and population control are the real goals of the eco-fascists, please have the intestinal fortitude to assert it thusly.

However, it would be more beneficial to have ADULTS reather than children be sacrificed. After all, adults are larger, weigh more and consume more than babies.

To accomplish the eco-fascists' goals, suppose we start by dispatching all homosexuals, criminally insane, retarded and ugly, overweight people. Sieg Heil!!

Neil Tagle, Hockessin, DE USA

The last thing I'll be thinking about is the environment when planning a family. That might be what the eco-terrorists think about while they burn SUV's and complain about the melting polar ice...

I'll be thinking about how I'm going to pay to send five kids to college, and providing for the family. Don't these hippies know smoking crack is adding to the greenenhouse gas emmissions?

Jim, Virionga, USA

Excellent, now I need to have three MORE out of spite!

William the Impeached, Buffalo, NY

This report and the opinions supporting it are frighteningly close to Third Reich Eugenics. Who decides whose children should be born and whose are an eco-crime, i.e. "Unwertes Leben"?

This report gives the term Eco-fascism a whole new dimension.

NE, London, UK

Why would someone want to limit couples from the joy of having as many children as they want for some personal aesthetic they have of how the think the earth best should be? How about live and let live? There's plenty of wilderness left in the world for those who want to find it.

In any case, in time problems associated with high population densities will be solved, as our technologies improve.

Robert , Seattle,

Tim in Bournemouth frowns at the unsustainability of the US per-capita resource utilisation. I hope he is not feeling too smug about the same statistics for the UK, as there is precious little difference from the point of view of the impoverished 80% of the world.

I'm still waiting for Al Gore to stand up and admit that his decision to have four children was a mistake. Maybe he could even tell us which two of the four he'd choose to pack off to the Soylent Green reprocessing centers in his ideal world.

Chris, Enfield, England

Europe is already choosing not to exist by having the lowest birthrates on earth. Of the 20 nations with the lowest birthrate, 19 are in Europe. Italy, Russia, Spain - all of these nations are beginning to cut their numbers in half with each generation.

You may say "great"! Less problems to deal with.

But wrong. Demographics is destiny, and while those responsible for the creation of Western civilization are choosing to breed themselves out of existence, the ENEMIES of Western civilization, particularly radical Islamists, are choosing to do the exact opposite.

Muslim birthrates are very high, which is the only reason France has such a high birthrate. They are moving into Europe in record numbers and now literally breeding Europeans out of the majority. In one more generation, two at most, Europe will be Eurabia, and your great free societies will now be just another Middle East, complete with Sharia law, lack of gay rights, subjugation of women, etc.

This is what you want?

Dunn, Fayetteville, USA

As a Green Party member let me reassure Michael FW: it is NOT Green Party policy to limit family sizes, and is highly unlikely ever to be. Labour and Tory 'Think Tanks' come up with equally ludicrous ideas at regular intervals, most of which are never heard of again; let this Green version have its moment of lunacy too.

Actually, they appear only to be advocating voluntary limitation, which we would have no quarrel with - though I doubt there would be very many takers.

Bill Linton, London,

This person must have his head in the clouds, or is it the sand. Does he realy believe that the Muslims people are going to cut down there population expansion when they want to rule the world. Or the Indian peoples are going to cut down on their children when they are needed to support the older members of the family. I would suggest that looks once more around the world and see it as it is, and will always be.

victor arram, westclff on sea, uk

As usual the experts concentrate on non issues. Co2 and more importantly methane emiissions will continue to rise whatever we do in Europ, Maybe they havent noticed but birthrates in India and Africa will continue their inexorable rise as will their co2 and methane emmisions as their living standard improve and more importantly as they industrialise.
Maybe we should think of having less cattle sheep and coal fired power stations per family. Maybe the experts should mention this to the developing world.

james, perth, western australia

This is nothing less than eco-facism, the Greens are now advocating Eugenics policies akin to those we more readily recognise in dictatorial nations of the far right and left.

This is one policy too far and will prevent me from even being tempted to vote for them.

the populations of many western nations are already in decline (Italy, Germany, France). if we have an average of 1.5 children per couple that would precipitate a drastic fall in population all over Europe.

Ask any economist population growth in the third world will be cured by pension rights. in every economy in the world population growth was only stabilised when affordable pensions, reasonable and trust-able were introduced

Indeed pensions are necessary for all kinds of thing like labour mobility and personal capital growth. it is typical of those who don't know their subject that they advocate force, "the last resort of the incompetent" to achieve their goals.

Michael FW, Snowdonia,

If the British fertility rate is 1.7, the EU average is 1.5. and some countries, such as France, are offering a financial incentive to women to have more babies, who exactly is overpopulating the world? In this case, it appears not to be white Europeans. I am sure you are not allowed to draw such a correlation.

Ruth Wollacott, Hornchurch Essex,

It always makes me laugh when people claim we need more children to look after an ageing population.

Talk about not looking further than the end of your nose. Who will look after them when they are elderly?

The majority of the worlds woes boil down to there being too many people on it. It is certain that there will be a 'correction', though it is up to us how painful this will be.

Simon, Cumbria,

In response to Eileen McCloy - I don't think anyone is questioning the potential productive capacity of her 10 children. It's rather their propensity to consume that is at issue. We have all seen the statistics that if the whole of the world's human population consumed at the rate of the US per capita then we would require the resources of many Earth sized worlds to support it. The arithmetic is very simple and the conclusion even simpler - there are aready too many people.

As to how to reduce that number - well I haven't yet seen any serious discussion. Perhaps "Bird Flu" is the answer. Or maybe other ways. I don't know. But until we start taking the subject seriously nothing will change.

All our efforts to reduce CO2 rpoduction will be pointless unless and until we tackle the issue.

Tim A, Bournemouth,

As this "debate widens", I'm just waiting for some 'expert' to say that its an 'eco-crime' to live past 70.

Michael Cope, Singapore,

The world has enough people already, many still living in dire circumstances

2 per women is more than enough

kev lax, Shanghai, china

"The pill was invented for a reason - use it, for goodness sake."
Gas chambers and atom bombs were invented for a reason - that doesn't mean that they were a good idea or that they should be used.

Bernard Mahan, Edinburgh, Scotland

Sorry, Eileen McCloy is wrong. There is no reason to have children to "look after our elderly" - and I'm sure in truth that was not her reason either. When will people understand that breeding like rabbits has already brought us into a situation where we're rapidly depleting the Earth's resources? The pill was invented for a reason - use it, for goodness sake.

Paulina Smid, London,

I do wonder how the Professor will explain his theories to Mother Nature.

Carol Bevitt, Nottingham, uk