It's time to talk about population stabilization.

Today, on Veterans' Day in the USA, I find myself thinking about the Baby Boom.

Like those of so many people born in the 1960s or 1950s, my parents married as wartime sweethearts. My mother was 18, my father 24. By 1945, when my eldest brother was born, hundreds of thousands of soldiers had arrived home, overjoyed still to be alive and reunited with their sweethearts.

It was rooted in the most endearing and palpable instinct known to humankind: reproduction. But on the scale of a World War and its aftermath, it created the demographic time-bomb we have known all our lives as the Baby Boom. And since 1968, when Paul and Anne Ehrlich of Stanford University published "The Population Bomb," even if with a timescale which proved inaccurate, many of us have known it by that name, too. (An interesting account of the marketing politics of that book can be found on Wikipedia: https://en.wikipedia.org/wiki/The_Population_Bomb.)

This past week, in 2019, a group of five of us scientists - along with over 11,000 scientist co-signatories from different fields - published a "World Scientists' Warning on a Climate Emergency" in the journal BioScience. We listed the stabilization of the world's human population as one of six core areas in which we need to make significant change in the next decade or so, if we are to have any reasonable hope of averting the partial collapse of economies, political systems, and societies around the world.

Just to be clear: the problems we face with climate change, in my view, are threefold: human population growth; wasteful and mindless consumption by the middle and upper classes; and an exploitative economy designed to fuel consumption, even at the cost of people and the planet. And, perhaps, fourthly: corrupt political landscapes in which corporate lobbying becomes more seductive to leaders than the needs of their constituents.

It's become starkly clear that this economic system was intentionally designed, and further tweaked by the architects of planned obsolescence, to extract and redistribute wealth, natural resources, and the fruits of labor from the poor to support the lifestyles of the middle class and the rich. It's been heading that way for centuries, although it's only become lethally toxic to the entire planet in our lifetimes, post-1950s.

It may be tempting to focus solely on the latter two issues of consumption and the economy, and pretend that runaway population growth isn't overheating both of them. But that would (continue to) be an egregious mistake.

All the gains in sustainable development in my lifetime - and seemingly my own life's work, so far - have been undermined by population growth, a runaway economy, and bad leadership. I am angry about that. Millions of us are. So it's one of the fires in my belly to shift this history - globally, locally, everywhere. I love this planet. I love babies. I do not want us to be heading over a cliff.

We treat the world as though it's an ever-expanding pie. Bad leaders and bad economists encourage that myth. They live in a parallel universe. It's a pie of fixed size - a finite planet. The pieces get smaller with every baby born whose birth is not cancelled out by someone else's death. It's a hard, gritty calculus. But unfortunately, we can't wish it away with Hallmark cards.

What makes us willing to ignore a ticking time-bomb of any description, especially one on a planetary scale? Well, we all know a few of the reasons. All of them I can understand - even if we all sense that we can no longer tiptoe around them:

1. Population growth is just plain awkward and hurtful to talk about with friends and family. All of us have friends, colleagues, nieces, nephews, siblings, children or even parents having babies. Or wanting to have a baby. There is nothing more precious, lovely, and to be celebrated than those milky, soft, innocent little bundles arriving within families which have been eagerly awaiting them. And while many new parents seem oblivious of the times, many others are deeply and achingly aware of their responsibility in raising children in these increasingly desperate times. These parents are taking big measures, sometimes at great personal and family costs, to lead on climate, environmental and social change, and to raise changemakers. So who is willing to be a killjoy? I'm certainly not. Let's celebrate the changemakers. But we also have to find a way to start, today, to stabilize our dangerously exponential population growth.

2. We also ignore this time-bomb and keep it in the Taboo category because population restraint seems unnatural. Breeding is our evolutionary imperative, and much of our human behavior - dating, coyness, ornamentation, competition, aggression - has evolved to facilitate it. We have hundreds of thousands of years of hominid evolution, and hundreds of millions of years of our deep animal DNA, steering us to those orgasmic moments at ovulation - and collectively, cumulatively, to this moment in time. So some people dismiss the whole conversation as unnatural and pointless. Birth strikers - women of conscience who choose not to have children - and those who wish to take control over when, where and how they have children, if at all - are still criticized, even ostracized, by too many (and way too many older men). They are even still called "selfish." It's time to stop, already!

I approach these things as most ecologists do: from the standpoint of the planet's carrying capacity. And from the perspective of density-dependent behaviors (like aggression, competition, and xenophobia) which increase as populations grow denser. And from the perspectives of what in the 1970s and -80s used to be called r- and K-selection -- in which "r-selected" rabbits breed when conditions are good, while long-lived, 'K-selected' elephants and long-lived humans have few babies and invest heavily in their rearing. (Beware, though - I've noticed that these labels have more recently been applied to US politics in a pretty facile, insidious way.)

But I also approach them as a mother, a woman, a lover, a friend. We are not just like mice, or even like elephants (with which we share so much: deeply social kin networks, loving parental care, keenly expressed grief at the loss of family members, and long memories). So we have the power - as we always keep saying to ourselves - to rise above all the instinctive imperatives of our genetic lineage.

3. Thirdly, population restraint (even birth control) has been an uncomfortable topic, in treacherous, choppy political and religious waters - due to faith teachings, and to the sinister agendas of the past, associated with fascism, eugenics, and coercive sterilization in Europe, Asia, Africa and beyond. The world has had several difficult, if ultimately at least partly demographically successful, experiments with nationally driven population control. So of course it's a deeply politicized subject - especially, seemingly, for men. We all know this, and so this discussion on a big, global scale needs to be honest, and frank, and deeply ethical.

Almost immediately last week, someone with clearly a very scanty read of our paper last week in BioScience, and the backgrounds of its authors, denounced our comments on population stabilization as "imperialism." They are annoying, of course, as they don't know us and haven't spoken with us. But they are probably right to challenge us: there's been a history of deep and nasty undercurrents of human behavior. We all need to acknowledge this, and be alert, as they could resurface at almost any time.

Critics are not right, though, to stifle the dialogue. It's way past time that we bring this sleeping elephant in the room back into the light.

For much of our lives, we've been fed a false narrative: that endless population growth is necessary to fuel endless economic growth. But we know now that this leads only to disaster. Some 1990s leaders, like Namibia's founding President Sam Nujoma, soon realized that his initial encouragement to his countrymen to have abundant babies would undermine, not accelerate, national development.

I've worked most of my adult life in Namibia and South Africa - and more briefly Uganda, Kenya and Tanzania - on biodiversity, climate change, and sustainable national development. I've been teaching at universities and working closely with many, many young women and men. In 34 years, I've worked with plenty of women students, friends and colleagues who simply want education, respect, quality of life, and a good future for their children. They don't want to be at the mercy of poverty, of economic or political marginalization, or of HIV/AIDS in societies which don't protect women from the political, economic and sexual domination they too often face.

Many African countries, like Rwanda, contrary to popular belief in much of the North, lead in women's political and economic emancipation.

But I have had at least three students or colleagues die of HIV/AIDS - all young women whose boyfriends or husbands had been unfaithful. Women are still too often culturally or economically unable to negotiate the power relationships which could save their lives.

So we need to have that global dialogue about population, equity, fairness and climate. Share this. Talk about it. Encourage respect, the sharing of ideas, and brainstorm how we can stabilize our planet back to a few billion people by the mid-22nd century or so. With mindfulness and support, and without coercion. That's the explicit hope of books like this one by Chris Tucker:

We need to reign in our population voluntarily, so that in the future, we are not forced by circumstances to do so. This needs to be a pressing, public dialogue with everyone's voices heard. Especially young women. Let's amplify this conversation, again - and stabilize our population voluntarily, and as quickly as possible -- before ecological crashes, epidemics, wars or demagogues take the matter out of our hands.