Black Swan events are proliferating for many reasons—notably climate change and the growing scale and interconnectedness of the human enterprise. World population doubled in the last half-century to just under seven billion people, so there are simply more people living in harm’s way, on geologic faults and along vulnerable coastlines. In effect, we have re-engineered the planet and ushered in a new era of radical instability. Advancing and securing women's rights are a key aspect of the solution to these problems.

This fall, world population will reach 7 billion people at a time of accelerated environmental disruption. This article is the first in a multi-part series commissioned by Rewire to examine the causes and consequences of population and environmental change from various perspectives and the policies and actions that need to be put in place to both avoid and mitigate the inevitable impacts of these changes.

Welcome to the age of the Black Swan.

The tornado that nearly leveled the city of Joplin, Missouri in May was a Black Swan; so was the 9.0 magnitude earthquake and tsunami that rocked Japan in March; and the “hundred-year floods” that now take place every couple of years in the American Midwest.

A Black Swan is a low-probability, high-impact event that tears at the very fabric of civilization. And they are becoming more common: weather-related disasters spiked in 2010, killing nearly 300,000 people and costing $130 billion.

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Black Swan events are proliferating for many reasons—notably climate change and the growing scale and interconnectedness of the human enterprise. World population doubled in the last half-century to just under seven billion people, so there are simply more people living in harm’s way, on geologic faults and along vulnerable coastlines. As the human enterprise has grown, we have reshaped natural systems to meet human needs, weakening resilience of ecosystems, and by extension our own. In effect, we have re-engineered the planet and ushered in a new era of radical instability.

At the same time, the world’s people are increasingly linked by systems of staggering complexity and size: think of electrical grids and financial markets. What were once local disasters now reverberate across the globe.

So what does this have to do with women’s rights, you may ask? A lot, as it turns out. The great challenge of the 21st century is to build societies that can cope with the flock of Black Swans that are headed our way. Advancing and securing women’s rights, especially reproductive rights, is central to meeting that challenge.

The New World, and How We Got Here

The age of the Black Swan marks a sharp turn on the long path of human history. It is hard to overstate how swiftly and profoundly we have transformed the way we live. Imagine that all of humanity’s existence was compressed into a 24-hour day, with each hour representing 100,000 years. Our humanoid ancestors first appeared at midnight, then spent the night and most of the following day hunting and gathering in small, mobile bands. At 11:56 pm, we invented agriculture. In the last seconds before the end of the day came the industrial revolution, the Pill, and The Jersey Shore.

Also in the last seconds before midnight, our numbers increased sevenfold, and—in the blink of an eye—we former hunter-gatherers had colonized every corner of the planet. Just think: it took from the beginning of human history until 1800 for our numbers to reach one billion. Now, just over 200 years later, there are nearly 7 billion of us. And we will likely reach 8 billion by 2025.

In many ways, the history of our species is an incredible success story. We’ve vanquished diseases, produced staggering quantities of food, and used our ingenuity to circumvent every drudgery and inconvenience. Some of us, at least, live in luxury that could scarcely have been imagined a few generations ago.

I got to thinking how far and how quickly we’ve come when I went looking for information about my maternal grandmother. I found her (on the web) in the painstakingly handwritten records of the 1910 census. There she was as an eight year-old girl, living in an apartment in Baltimore with her grandparents, mother, a couple of siblings, and some random boarders taken in to help pay the bills.

Consider her environmental footprint. Her family didn’t have a car, or electricity, or even indoor plumbing—chamber pots and an outdoor privy sufficed. She ate organically grown, local produce (there wasn’t any other kind; pesticides and synthetic fertilizer weren’t yet widely used). Meat was a luxury. No plastics. No airplanes. No petrochemicals.

Believe me, I don’t idealize the past (I am very, very fond of indoor plumbing). But I am struck by how much our family’s environmental impact has grown in the space of two generations. My family of four lives in a house twice the size of the apartment my grandmother shared with seven others. Between my ailing Subaru, my central air conditioning, and the occasional airplane flight, I produce well over 20 tons of the greenhouse gas carbon dioxide each year. My grandmother, burning a few lumps of coal for heat in the winter, likely produced a tenth as much.

Moreover, my out-sized consumption habits are shared by a much larger number of people. When my grandmother was a kid, there were 92 million Americans, today there are 308 million. Globally, our numbers grew from 1.75 billion to nearly 7 billion in that time. While most of the world’s people do not consume resources as rapaciously as Americans (more on that later), it is safe to say that both human numbers and consumption have skyrocketed in the space of a few generations.

The Dark Side

Which gets me to the dark side of the human success story. In our brief stint of planetary dominion, we have done a vast amount of damage. We have replaced the riotous diversity of nature with uniform monocultures. We’ve changed the chemistry of earth and sky—increasing the carbon dioxide in the atmosphere by 40 percent, and acidifying the oceans. We’ve cut down nearly half of the planet’s forests, and destroyed two-thirds of its coral reefs and mangroves. We have brought about the greatest mass extinction of plant and animal life in our history; every year, some 30,000 species become extinct (about three per hour).

Nature is inherently resilient; ecosystems regenerate after disturbances like hurricanes and wildfires. But we have weakened nature’s ability to bounce back by removing key species, by harvesting resources more rapidly than they can renew themselves, and by loading ecosystems with more wastes than they can absorb.

In so doing, we’ve weakened our own resilience. Healthy ecosystems are the foundation of human well-being; they provide a range of essential goods and services to humankind, such as food and freshwater, pollination, and protection from storms. As a result of our chipping away at that foundation, a recent global survey found that the “the ability of the planet’s ecosystems to sustain future generations can no longer be taken for granted.”

And, as we have weakened human and natural resilience, we have created new threats. Human-induced climate change has ushered in an unknowable future of intense storms, floods, and droughts. As NASA climate scientist Dr. James Hansen puts it, “Ten thousand years of good weather is over.” Cue the Black Swans.

Of course, not all humans are equally culpable for this state of affairs. And that illuminates the other dark aspect of our species’ success: staggering inequity. The unprecedented affluence that some humans now enjoy has not been evenly shared; some 40 percent of the world’s people—2.6 billion—still live on less than $2 per day.

Most of the world’s poor have environmental footprints that resemble my grandmother’s more than my own. The average citizen of Tanzania, for example, emits about a tenth of a ton of CO 2 per year—about what the average American puts out every 28 hours. But, tragically, it is the poor—those who contributed least to the sacking of the planet—who are most vulnerable to the consequences of environmental decline.

So, to recap: humans have had a good long run, but in the process of establishing dominion over the Earth, we’ve weakened the support systems that have enabled us to thrive thus far. We have altered our planet in fundamental ways, ushering in the age of the Black Swan—a period of instability and suffering—with the poor and vulnerable at greatest risk.

This is, admittedly, a bleak picture. The good news is that it is possible to build more sustainable and resilient societies, and to limit damage to the natural systems that we depend upon. And that is where women’s rights—including reproductive rights—come in.

Sustainability and Scale

Environmental sustainability is, in part, about how a society uses resources. On the simplest level, if resource use is unsustainable, you can’t keep doing it. If you take fish from the ocean faster than the fish can reproduce, you run out of fish. (Of course, affluent countries and people typically get around this problem by helping themselves to other people’s fish.)

But collectively, humans are using resources more quickly than they can regenerate: two thirds of the planet’s ecosystems—including fisheries and fresh water—are now being used in ways that simply cannot be sustained.

Sustainability is a function of the scale of the human enterprise; of the way we consume resources, on one hand, and of the number of consumers on the other. On a finite planet, neither human numbers nor human appetites can grow forever.

For those of us who live in the United States and other countries that devour a disproportionate share of the planet’s resources, reducing consumption is the top priority. It can be done, with a wholesale shift from fossil fuels to renewable energy, greater efficiency, cities and towns built around reliable public transportation, and food systems that encourage us to eat lower on the food chain. Fundamentally, we need to reorient our economy from the production and consumption of goods of dubious value to a new emphasis on meeting human needs.

UN Population projections, High (red), Medium (yellow) and Low (green).

And, as human numbers approach 7 billion, people everywhere need to think about where we go from here.

The United Nations recently published new population projections, which envision a range of possibilities for the 21st century. If fertility rates stay where they are today, we’d pass 26 billion by the end of this century. But that’s not likely: thanks to wider availability of contraception, urbanization, and other factors, fertility rates have fallen steadily in recent decades, from an average of 5 children per woman in 1950 to just 2.5 today. The question is how quickly, and how steeply, they will continue to fall.

In the UN’s low projection, fertility dips to 1.7 children per woman and human numbers peak at 8 billion by mid-century, then decline to 6 billion by 2100. By contrast, the medium and high projections envision slower declines in fertility—and continued growth for the foreseeable future. The medium projection would reach 10 billion by 2100; the high projection, nearly 16 billion.

I don’t believe there is an optimal size for the human population; greater equity and more efficient use of resources would greatly extend the planet’s “carrying capacity.” But, when you consider the resource challenges of the 21st century, and the unpredictable new era we have entered, 8 billion looks more sustainable than 16 billion.

Take water, for example. While there is no global shortage of freshwater, a growing number of regions are chronically parched. And many of those regions—including parts of Africa, the Middle East, and Asia—are also where population is growing most rapidly. The World Bank has identified 45 “water-poor” countries where shortages are especially acute. Those countries have an average fertility rate of 4.8 children per woman—nearly twice the world average. And their populations are expected to double by 2050.

Slower population growth is not a panacea for the world’s water problems. Much can be done to develop better technology and better policies on water use. But slower growth and smaller population numbers could help ease pressure on scarce resources. That’s true for countries dealing with the deadly combination of poverty and water scarcity—and it’s true for the world as a whole.

Population and Women’s Rights

The difference between 8 billion and 16 billion is all about women’s rights. Fertility rates have fallen in most of the world’s countries, but they remain high where women’s status is low.

Less than one-fifth of the world’s countries will account for nearly all of the world’s population growth this century. Not coincidentally, those countries—the least developed nations in sub-Saharan Africa, south Asia, and elsewhere—are also where girls are less likely to attend school, where child marriage is common, and where women lack the means and the power to make their own decisions about childbearing.

That can change. Nations can raise women’s status by educating girls, by enforcing laws that prohibit child marriage and sexual violence, and by improving women’s access to credit, land, jobs, and training. Where women enjoy these fundamental rights, smaller (and healthier) families become the norm.

At the same time, women must have the means to make choices: family planning and other reproductive health services. Around the world, some 215 million want to avoid pregnancy, but aren’t using effective methods of contraception. Fulfilling that “unmet need” for family planning is vital to ensuring women’s reproductive rights, and to slowing population growth. In this way, the goals of the sexual and reproductive health and rights movement are deeply aligned with the imperatives of environmental sustainability.

A Three-Legged Stool

Achieving a sustainable balance among people, consumption, and resources is necessary and important. But it is not sufficient.

We have entered an era of unpredictable, wrenching, change. Consider the climate: even if we ceased emitting greenhouse gases today, the legacy of past emissions guarantees a future of warming temperatures, stronger storms, and rising seas.

To thrive in the face of these changes, our societies must be resilient—they must be able to absorb disturbance while continuing to function. What makes a society resilient? There is a substantial—and growing—literature on this subject; a few points bear repeating here.

Some characterize resilience as a three legged stool: the “legs” of the stool include a nation’s environmental capacity—the health of its ecosystems; its human and civic resources; and its economic capacity, or wealth.

Women have an important role to play in bolstering each leg of resilience. First, environmental capacity: in much of the developing world, women are primary caretakers of natural resources such as forests and freshwater. Empowering women with property rights and decision-making authority can result in better stewardship of those ecosystems. That’s what happened in Gujarat, India: when women were well-represented on community forest management committees, forest conditions improved dramatically.

Second, human resources. Women’s power, knowledge, and creativity are vital—but underutilized—human resources. Girls and women are often held back; they get less food, less medical care, less formal education, and fewer opportunities than their male counterparts. Investing in girls and women yields enormous benefits. For example, girls’ education is associated with a vast range of positive outcomes, from higher crop yields to lower rates of HIV and better nutrition.

Finally, economic capacity: A growing body of research shows that ensuring economic opportunity for women may be the best way to end world poverty. This is not only because women are at a greater risk of being poor, but also because women in poor countries are more likely to spend their income on food, education, and health care for their children—giving families a lasting path out of poverty.

The growing risk of Black Swan events lends urgency to improving women’s status, because women are among the most vulnerable in times of crisis. In the 2004 South Asian tsunami, for example, three times as many women died as did men. Why? In part because of rigid gender roles; not only did women shoulder the burden of saving children and the elderly, their traditional clothing made it difficult to move quickly, and—unlike their brothers—they had not been taught to swim. Addressing women’s vulnerabilities is a top priority for any effort to build resilience.

Of Rights and Resilience

We can’t know what the age of the Black Swan has in store for us. We have never been here before; the environmental and social challenges we face today are utterly without precedent. But change—sweeping and transformative—is a constant in natural and human history. We can embrace change and prepare for it by building sustainable, resilient societies.

To do so, we need to ramp up our efforts to ensure women’s rights. In an age of uncertainty, no nation can afford to squander half of its human capital. And, where women enjoy equal rights, societies are healthier, more prosperous, and less vulnerable.

At the same time, we need to find a sustainable balance among people, consumption, and resources. That means intentionally downsizing the scale and impact of the human enterprise, by reducing wasteful consumption and by choosing a slower growth path for human numbers. Here, too, women’s rights—especially reproductive rights—are key.

When I think about the paths our numbers could take, I am again reminded of my grandmother. On the 1910 census where I found her name, there were two columns that no longer appear on census forms: “number of children born” and “number now living.” Often, there was a large gap between the two. My grandmother’s grandmother had ten children; five survived. Her mother had six kids; just three were alive in 1910.

Those numbers are a reminder of the brutal way in which human population was held in check throughout most of our history: high fertility was balanced by high mortality. Our numbers soared with the advent of sanitation and vaccines, because more children survived to adulthood. When mortality rates fell, fertility rates often followed, and a new equilibrium was achieved. But that equilibrium remains elusive in many parts of the world, where women still lack the means and the power to make their own decisions about childbearing.

The numbers remind us, also, that the sustainable, resilient world we seek is in the future, not in the past. We can’t go back, nor would we want to. We can, however, go forward—by curbing our environmental impact, by advancing the rights of women, and by unleashing the intelligence and creativity of every one of the planet’s 7 billion citizens.