We don't like to talk about it, but looking around at the state of the world you wouldn't be too crazy to conclude that maybe, just maybe, there are too many of us. That's, people. Humans.
Given that we all want a car, a fridge, an overseas holiday as well as clean air, water and food, it could well be time to take our collective human foot off the reproductive peddle.
Sure there are some people that are benefitting from our swelling numbers like big business and rich people, large scale farmers, real estate agents, developers. Of course economists love it when populations are growing, it's the simplest way hands down to grow economies and make the bottom line look good, and if they are happy then our politicians are too. More people means more cars, more houses, more TVs, more jobs. Everyone looks good. Conversely the prospect of a shrinking population sends the stake holders into panic mode warning of 'aging' populations and demographic tsunamis and skills shortages. Not surprisingly, 'have more babies for the good of us all' is the message we are drip fed.
But while some people undoubtedly benefit from population growth you've got to wonder if most of us are shooting ourselves in the foot. I'm thinking about the hundreds of millions of people carmmed into squalid shanty towns on the edges of dystopian magacities, or the one billion people who don’t have enough food to eat or clean water to drink, or the millions of displaced people clamouring at closed borders or the mothers-to-be who are too afraid to breathe in case the polluted air damages their unborn children, or the children living on rivers flowing toxic green with industrial waste or the fishers whose nets drag in plastic bottles instead of fish.
Some people may celebrate the fact that the number of cars in the world is set to double in the next 15 years but not me, I'm more worried that climate change is about to unleash a swathe of destructive forces upon us that will make the current numbers of refugees pushing to enter developed countries look like a trickle.
Then of course there's the unfettered destruction of the natural world - forests, ecosystems, oceans - and the holocaust of other species we share this planet with which for some of us, is a heart breaking tragedy we feel powerless to stop.
From an ecological point of view the future is kind of bleak. It's estimated that at current rates of fishing the oceans will be empty by 2048, of fish, not plastic. And the statistics to do with draining of aquifers, destruction of arable land and deforestation are horrifying.
Seven going on 8 billion people, given the way we choose to live right now, is a real burden on our natural resources. And the prospect of another billion or more in just 20 years is frankly horrifying. Today 863 million people live in slums. It's a startling figure but what will it be in 20 years?
You've got to wonder if the days where population growth added to human happiness are over. I can imagine in a cave or an isolated agrarian village, safety in numbers were good. And there's no doubt that two heads prove better than one when growing our knowledge base or fueling technological innovation. Economies of scale drove the agrarian and industrial revolutions providing an unlimited supply of innovators, labourers and consumers. A critical mass has always been a good thing and economic growth has given a record number of people around the world a rising standard of living.
Eight, nine or even ten billion people won’t kill us, it’s not apocalyptic, it’s not a human time bomb getting ready to explode, what’s under threat is the quality of life of those humans, not life itself.
No doubt 8 billion people is supportable with advances in agricultural productivity, but life is a gift, it should be lived with dignity, purpose and happiness, not endured on a rubbish heap.
Most of us believe that science will come to the rescue and it's true, we are making remarkable changes in the way we live. Our efforts to feed so many and tackle each environmental problem as it arises is admirable.
The Climate Change Conference in Paris in 2015 was a huge milestone in humanity's ablity to work together for the common good. We are more innovative in our recycling and waste reduction, more scientific in our agricultural production, cleverer in our use of energy, more sustainable and efficient in everything we do.
But every innovation, every efficiency, every clever solution is negated by the addition of 227,000 new humans every day. It's one step forward two steps back.
Still no one talks about population growth. It wasn't discussed in Paris, it's not on the table at Davos, ever.
Why is this? It's partly because the people who determine the political and econoimic agenda are the very people who benefit from population growth, the rich and the powerful. But it's also because the solutions to date like China's coercive One Child Policy or India's forced sterilisations are more scary than the problem.
So what do we do?
Well right now we're all hoping it just kind of solves itself some time in the future. The International Institute for Applied Systems Analysis estimates the world population will peak at 9.5 billion in 2070 and then stabilise. Others estimate it'll be a lot more.
What if millions of people due to start a family in the next 20 years chose to stop at one child? Not because they were paid to or forced to, but because they decided it was best for themselves and their child.
The fact is for a growing number of people across the globe, choosing to have one child is best for themselves and their child, both economically and personally.
These people belong to the bourgeoning urbanised, educated, middle class in just about every country on earth. If you are one of these people stopping at one child makes a lot of sense. These people are ebing squeezed by the cost of housing, food, childcare and educaiton. They already work long hours and they are accutely aware of the role a good education plays in securing better paid employment and are willing to pay for it.
Many are already choosing to have one child but for many others, choosing a family size isn't a decision they make based strictly on research and reason. Many couples like shopping for a car or holiday, on tradition, emotion and in many cases outdated myths. Instead of a Prius they're buying an old gas guzzling Chevvy because that's what their parents think they should do.
The fact is stopping at one child is the economically rational and environmentally responsible choice for affluent middle class urbanites who want to maximise their family's happiness.
Acccording to recent research by Hans-Peter Kohler a sociologist at the University of Pensylvannia mothers experience a flush of happiness after their first child but when the second child is born they actually feel a decrease in happiness which never goes away.
Women have suspected this were true for some time which is just one of the reasons why in places where women have access to contraception, education, careers and choice, they have smaller families.
But stopping at one for the sake of your own happiness would be selfish if the research showed that only children were either deficient or unhappy.
Well they're not unhappy in fact according to one of the widest ranging research projects on family life in Britain children are happier the fewer siblings they have with only children being the happiest of all.
A growing body of research has consistently shown that the diminution of parental time associated with adding siblings and increasing family size adversely effects the cognitive and behavioural outcomes of children and this results in lower educational outcomes and lower wages in adulthood.
Siblings are also coming under scrutiny as more researchers defy taboos and put this elemental human relationship under the microscope like never before. In one study a third of children report experiencing repeated and sustained bullying by a sibling leading to long term psychological effects equivalent or worse than that caused by peer bullying including self harm, depression, anxiety and lower self esteem.
Other research is focussing on the damage inflicted on children when parental favouritism is present in the home. Study estimates that upwards of 60% of families suffer parental favouritism and that both favoured and unfavoured children suffer from long term psychological damage.
Birth order is another cause of inherent unfairness in multisibling families with an avalanche of research now showing that first born children usually receive the lions share of parental attention, time, resources and expectations. Later born children have been shown to have lower IQs, lower educational outcomes and even behavioural problems.
Of course it's not just parental time that can effect a child's future, a major factor contributing to the happiness of children and their parents is financial security. It's estimated that raising in a child in the US costs more than $240,000, that's five times the average annual wage. The costs are broken down into categories of housing (30 percent), child care and education (18 percent), food (16 percent), transportation (14 percent), health care (eight percent), clothing (six percent), and everything else.
Of course the urbanised middle class will all be feeling the rising costs of housing, child care and education, no matter where you live. From Beijing to Berlin to Mumbai living in big cities is expensive and demands both parents work, which is why childcare is the next big ticket item.
Of course you might like to consider too that only children have never been shown to be in any way socially different from other children, even when you take into account over 115 studies over 60 years. Research shows that only children are indistinguishable from their siblinged peers on every social measure. And they are unlikely to be lonely or even alone living as they do in high density urban centres where they share community spaces like playgrounds, dog parks, cafes and swimming pools when they're not at school or in childcare.
Older children and teens have access to smart phones, social media, skype and online gaming and are in constant contact with their friends and social groupings. These days teens have friends across the street, the city and the planet. With all those peers on tap it's a wonder siblings get a look in.
Most importantly, the stigma of the only child as an oddity or rarity is gone. Across the globe one child families are on the rise with the largest numbers in middle class, urban centres. In the UK one child families will be in the majority in less than a decade. In India and Asia, the upwardly mobile middle classes are increasingly choosing one child. In the US one third of families in the big urban centres like New York City have one child., In Australia and most of Europe one third of families have one child.
Only children are becoming the new norm and with that comes a social force for change.
Families with one child reach out to each other, join together on holidays and vacations, make play dates, share each others spaces. Only children form bonds with friends or cousins, their parents form friendships. As parents of only children, we are making the world ony-friendly.
Of course it's the very lifestyle I'm describing that generates the added imperative for parents to stop at one: the environmental imperative. It's this affluent, Western, materialistic, energy hungry lifestyle that is fueling global warming.
Let's face it, you don't buy a Prius or a Tesla just because it's good looking, comfortable and efficient, you buy it because you want to make a difference. Likewise Toyota or Tesla woudln't be selling their do-good cars if they were ugly, unrliable and cramped.
Think of your family as a beautiful new Tesla or a practical Prius, you buy them because they make you feel good, but also because they make you happy.
So it you're worried about the state of the world, get on board. Be happy. Go once.
A billion selfish decisions could buy us critical time to save our planet, one child at a time.