The politics of world demographics is extremely interesting, mainly because it captures most of the big partisan debates on global development and environmental protection, for example, debates on the earth's "carrying capacity," the relationship between population and poverty, family planning (in both the advanced and developing worlds), and climate change. Depending on who you talk to, the world is nowhere near its limit of human population sustainability. Indeed, the sky-is-falling naysayers, Stanford University demographer Paul Ehrlich, especially, were proved so wrong with their 1970s-era predictions, that international attention to population change dropped off the radar. Robert Zubrin talks about the hysteria here: "The Population Control Holocaust."
In any case, here's the key alarmist passage from the Times' piece:
The relentless growth in population might seem paradoxical given that the world's average birthrate has been slowly falling for decades. Humanity's numbers continue to climb because of what scientists call population momentum.And check back at the article for some cool graphics.
So many people are now in their prime reproductive years — the result of unchecked fertility in decades past, coupled with reduced child mortality — that even modest rates of childbearing yield huge increases.
"We're still adding more than 70 million people to the planet every year — which we have been doing since the 1970s," said John Bongaarts, a leading demographer and vice president of the nonprofit Population Council in New York. "We're still in the steep part of the curve."
Think of population growth as a speeding train. When the engineer applies the brakes, the train doesn't stop immediately. Momentum propels it forward a considerable distance before it finally comes to a halt.
U.N. demographers once believed the train would stop around 2075. Now they say world population will continue growing into the next century.
In India, a country of 1.2 billion people, women have an average of 2.5 children each, and the birthrate is projected to fall to 2.1 by 2030. At that point, parents will merely be replacing themselves.
But even then, India's population will continue to grow because of momentum. It is on track to surpass China's and is not expected to peak until 2060, at 1.7 billion people.
Momentum isn't the only factor in population growth. In some of the poorest parts of the world, fertility rates remain high, driven by tradition, religion, the inferior status of women and limited access to contraception.
Population will rise most rapidly in places least able to handle it: developing nations where hunger, political instability and environmental degradation are already pervasive.
The African continent is expected to double in population by the middle of this century, adding 1 billion people despite the ravages of AIDS and malnutrition.
Even under optimistic assumptions, the toll on people and the planet will be severe.
Today, about 1 in 8 people in the world lives in a slum. By midcentury, with the population at more than 9 billion, the ratio would be 1 in 3, assuming poverty and migration to cities continue at their current rates.
Now nearly 1 billion people are chronically hungry, according to the U.N. Food and Agriculture Organization, and at least 8 million die every year of hunger-related illnesses.
By midcentury, there will be at least 2 billion more mouths to feed, and no one can say where the food will come from.
It's not just that the population will be larger. It's that hundreds of millions of newly affluent people, mostly in Asia, will want to add dairy products and grain-fed beef and pork to their diets.
To meet the projected demand, the world's farmers will have to double their crop production, according to calculations by a team of scientists led by David Tilman, a University of Minnesota expert on global agriculture.
William G. Lesher, a former chief economist for the U.S. Department of Agriculture, said the brightest minds in the field haven't figured out the solution.
"We're going to have to produce more food in the next 40 years than we have the last 10,000," he said. "Some people say we'll just add more land or more water. But we're not going to do much of either."
Most of Earth's best farmland has already come under hoof or plow, and farmers are losing ground to expanding cities and deserts. Soil erosion, chemical contamination and salt buildup from irrigation are despoiling prime acreage.
Climate change will make all of these challenges more daunting. Higher temperatures and violent weather will stunt or destroy crops. Increased flooding will imperil millions living in low-lying regions. More severe droughts could displace masses of people, leading to conflict.
By 2050, the United Nations predicts, there could be as many as 200 million "climate refugees."
Despite these trends, population growth has all but vanished from public discourse.
In Europe, Japan and North America, leaders are worried about having too few young people to care for aging populations and to fund benefits for the elderly.
In developing countries, leaders often consider large youthful populations a source of economic vitality and political strength.
In the U.S., contraception has become entangled in acrimonious battles over abortion, causing some environmental and humanitarian groups to retreat from family planning initiatives.
Under the best conditions, it's hard to get contraceptives into the hands of impoverished women who want them. In developing nations, family planning programs open and close at the whim of autocrats. Aid from wealthy nations rises and falls with political currents.
The result: Nearly 20 years after 179 nations signed a pledge to provide universal access to family planning, supplies of contraceptives remain erratic in much of the developing world.
Population growth gets less attention than it did in the late 1960s, when there were half as many people on the planet.
RELATED: From Bjørn Lomborg, at Foreign Affairs, "Environmental Alarmism, Then: The Club of Rome’s Problem -- and Ours and Now."
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