The UN World Population Prospects projections forecast: that the world will reach nearly 11 billion people by 2100 presents an unsettling prospect of an unfolding population growth related humanitarian tragedy, one that reflects a collective failure to provide women world wide with safe, effective ways to avoid pregnancies they neither intend nor want. It is also a grim reminder of how overpopulation is a substantial liability against the dreams of a sustainable future living scenario between humans and our planet.

Bob Engelman, President of Worldwatch Institute, writing on the Yale University website (here slighted edited), reports on the UN’s projections and assesses the consequences of relentless population growth globally.

Until recently, the great global food challenge was how to feed 9 billion people in 2050. But no longer – the number of mid-century mouths just jumped. Now it’s projected to be 9.6 billion, closing in on double-digit billions. And forget expectations that world population will stabilize this century: By 2100, according to the latest UN projections, people on the planet will number 10.9 billion – and will still be growing by 10 million a year.

These hundreds of millions of unanticipated future humans come from the “medium-fertility,” or best-guess, calculations of UN demographers, in their 2013 biannual projections of future world population growth. And what a surprise their calculations are, dashing the hopes of optimists who assumed that human fertility was falling everywhere and that population growth would end “on its own” within a few decades.

What’s interesting about the new projections, however, isn’t what they say about future populations. Not even demographers know how many people will be living 50 years from now. What’s interesting is what the numbers say about today’s 7.2 billion humans. Because what the new projections say, and loudly, based the 2010 round of country censuses, is that women in many of the world’s poorest and most conflict-prone countries are having significantly more children than previously thought, largely because many governments are no longer making family planning a high priority.

Only 10 years ago, the UN Population Division was projecting there would be no more than 8.9 billion people alive in 2050. That number has just jumped by 700 million – an increase nearly as large as the population of Europe.

Afghanistan’s current fertility rate – the average number of children each woman has over her lifetime – is now estimated at 6.3, compared to 5.1 previously. Women in South Sudan average 5.4 children, up from the earlier estimate of 3.8. For East Timor it’s 6.5, up from 5.7. For Somalia, 7.1 compared to 6.7. For Ethiopia, 5.3 vs. 4.8. And the list of boosted fertility estimates – some reflecting real fertility increases, some just improvements on past estimates – goes on. The UN Population Division raised by a full 5 percent its assessments of fertility in 15 sub-Saharan countries where most women give birth many times.

In a world of changing climate, shrinking farm plots, dwindling fresh water supplies and growing social stress, these higher assessments of family size in fast-growing, low-income countries is bad news. What the new fertility estimates reflect is not just counting errors but a collective failure to provide women around the world with something they need that men don’t have to ask for: safe and effective ways to avoid pregnancies they neither intend nor want, along with the education and autonomy to put their childbearing decisions into effect.

About two out of five pregnancies worldwide are unintended, according to the Guttmacher Institute, a respected reproductive-health think tank. Intriguingly, that proportion is as high on average in the high-consuming developed world, despite our sophisticated health systems, as in the developing one. An estimated 222 million women in developing countries are sexually active and do not want to become pregnant, yet are not using effective contraception, health surveys show. It would take a mere US$8.1 billion – a rounding error in today’s $80-trillion global economy-to supply the family planning services that would shrink this number close to zero, the Guttmacher Institute estimates. But the world spends less than half that.

Pinched funding for family planning and reproductive health reflects larger obstacles to a sustainable world population. In no country have women achieved real equality with men. In some they are still seen essentially as male property. And in few societies is there full acceptance that sexuality is not only essential to reproduction but meaningful and valuable even when reproduction is not intended. Sex education is non-existent in many countries and scarcely adequate in any. Contraception gets confused with abortion and even in the United States (and Canada?) is associated with promiscuity – witness controversies surrounding the contraceptive insurance mandate in Obamacare.

On the other side of the planet, the Catholic Church for years has blocked the government of the Philippines (fertility rate: 3.3 children per woman, second highest in eastern Asia) from providing free family planning services to all who seek them. Although President Benigno Aquino recently signed a bill to do just that, the Church has taken the matter to the Supreme Court which has put a hold on the law’s implementation prior to its review. And most justices are reported sympathetic to the bishops’ opposition to modern contraception.

Secular and affluent subsets of the global population can hardly be smug about these matters. The truth is that few of us are comfortable addressing either the need to improve family planning services and sexuality education or the growth of world population itself. Population, in particular has been off the table of public and governmental discourse for two decades. By unspoken agreement, world leaders have come to see the issue as too sensitive to bring up. The worry appears to be that it offends the anti-contraception Catholic Church, as well as some women’s rights advocates and leaders of high-fertility countries, those who argue that the consumption of the wealthy is a greater threat to humanity than continued population growth.

The UN’s latest projections are a blunt reminder of the consequences of our silence. No end to global population growth is in sight. Nor will one be until we resolve to act on women’s autonomy, the dignity of sex without reproduction, and the importance of a non-growing population to environmental sustainability.

Advocates of pro-active population policies – based on human rights and individual intention rather than on coercive population control – have been making a key point for decades: Without an eventual end to population growth, our physical world of finite natural resources will inevitably witness increases in death rates from disease, starvation, and/or violent conflict. UN demographers seem not to be on speaking terms with their scientific colleagues who study climate change, the planet’s ecosystems and natural resources. At the least, the former are not grasping what the latter are projecting for humanity based on their own expertise.

To be fair, demographers themselves acknowledge that projections are at best educated guesses based on past and present human data. John Wilmoth, the UN Population Division’s director, told the Associated Press that “there is a great deal of uncertainty about population trends.” The impact of potentially devastating epidemics – already the world sees more than five new infectious diseases each year (ebola being the latest), according to a study by parasitologist Peter Daszak and colleagues – is just one such unknown. Nonetheless, pundits, press, and public assume demographic experts are confidently and competently predicting the future of human population. And this future presupposes that no level of human presence on the planet will ever undermine its capacity to support human life.

So the projections present us with the optimistic presumption that in 2100 human life expectancy worldwide will average 82 years, up from 70 today – despite growing resource scarcity and temperature increases likely to have blasted through the 2-degrees-Celsius ceiling that climate scientists and governments agree is dangerous to exceed. Nigeria’s population is projected to quintuple from 184 million today to 914 million in 2100. The country’s development is already hobbled by violent conflict, government corruption, untreated waste, and rampant oil spills – not to mention an inequitable economic reliance on oil that is unlikely to keep gushing at current rates for 87 more years. It’s difficult to imagine Nigeria heading toward 1 billion human beings as the country’s less-than-abundant natural assets of renewable fresh water and arable land shrink by roughly 80 percent on a per-capita basis.

Egypt and Ethiopia are rattling sabers even today over their common dependence on Nile waters as Ethiopia harnesses its flow for hydro power. These countries will see their combined population more than double, from 176 million to 379 million. Jordan is already challenged to share scarce water supply with an influx of Syrian refugees who have substantially boosted its population of 7.3 million, and native Jordanian alone are projected to increase by that 500,000 in just three years – and by 78 percent by 2100.

People in all these countries are innovative and resourceful. No doubt technological advances we can’t possibly imagine today will contribute to health and long life. Maybe we’ll soon make real progress in addressing climate change and water scarcity. But all those who believe that such large populations are likely to be living in these countries – and with 82-year life expectancies no less – at the end of this environmentally challenged century, please raise your hands. The rest of us need to start taking the rights and potential of women, the importance of sex for its own sake, and the impact of human numbers on the environment a lot more seriously than we do today. (Ends)