Shaking the baby tree: if there's a "depopulation bomb," it has a very long fuse.

No one told Salamatou Adamou about the "birth dearth." A midwife and widow, she had already given birth to 12 children by the age of 37. "I am exhausted" she said as she struggled through labor with child number 13. Her large family is not all that unusual in drought-stricken Niger, a country where widespread poverty combines with strict patriarchy, early marriages, a lack of health care access and educational opportunities for women, sanctioned polygamy and adherence to fundamentalist Islamic tenets on procreation to produce the highest birth rate in the world, eight children for every woman.

The birth dearth is certainly real enough; declining birth rates (also known as fertility rates) are evident in many parts of the world. The effect is particularly dramatic in developed countries, where the specter of a graying population with soaring health care costs is raising alarms. It takes two children to replace parents, so a birth rate of 2.1 is called "replacement level." But in Germany and Japan the total fertility rate, or TFR, is 1.4; in Italy, Russia and Spain it's 1.3. Russian President Vladimir Putin wants to pay women to have children, because he says his country is losing 700,000 people per year.

At these rates, affected countries face real population declines, and that fact has been making headlines. It's news when Australia's treasurer, Peter Costello, gets so concerned about the country's 1.73 birth rate that he urges families to "have one for mum, one for dad and one for the country. Procreate and cherish."

But the birth dearth is far from universal, and some of the world's poorest (such as Niger) and most populous (like India) countries are still experiencing rapid population growth, enough to make it likely that, according to the United Nations' median projection, the world (now at 6.5 billion people) will have at least nine billion as early as 2050. Meanwhile, the U.S., with just above replacement-level fertility but high immigration, is hitting the 300 million mark. And the Census Bureau predicts that 400 million will be reached in less than 40 years.

The African Example

Let's look at what's happening on the ground in two of the most challenged countries in sub-Saharan Africa, Niger and Kenya. Two thirds of Niger's population of 14 million people live below the absolute poverty level on less than a dollar a day, and most of the poorest are women. The drought and a plague of locusts made 2.5 million dependent on international food relief last year, and 32,000 children were victims of severe malnutrition.

Because of its high birth rate, the West African nation of Niger (twice the size of Texas) is a very young country, with almost half its population (48.9 percent) under age 14. But life expectancy is only 41, near the bottom of world charts. More than a quarter of all children born in Niger fail to reach their fifth birthdays. Eighty-five percent of births take place at home, and for every 100,000 live births, 920 mothers die. Just four percent of women use modern methods of contraception, and abortion is illegal. The country has the lowest adult literacy rate in the world, only 17 percent.

According to a spokesperson for the Embassy of Niger in Washington, D.C., "There are many reasons for our high birth rate: People are not educated, and they see children as a kind of asset. We are also a Moslem country, so birth control is not favored as it might be in developed countries."

Clearly, high birth rates contribute to Niger's manifold problems--it could have 50 million people by 2050--but the factors that keep the rates high are likely to remain in place for the foreseeable future. Nor are other countries in Africa (which has the world's highest rates overall) necessarily seeing declines. Kenya is a particularly striking case in point: its population rose from 5.4 million in 1948 to more than 30 million today with birth rates as high as 8.1. By the period between 1995 and 1998, a long decline had reduced the rate to 4.7. It seemed to be stepping into line with world trends.

But according to the CIA World Factbook, Kenyan fertility hit a plateau that it has maintained for the last decade. A report by Charles Westoff of the Office of Population Research at Princeton University shows that the birth rate actually increased slightly between the surveys of 1998 and 2003, from 4.7 to 4.8. "It was plummeting, but now it's stagnant;' says Bob Engelman, a vice president at Population Action International.

According to the Nairobi-based Nation newspaper, the main reason for the birth rate stagnation and increase is "erratic supply of contraceptives, particularly the pill, after donors, who provide over 80 percent of the funds, decided to channel a substantial amount of their resources toward HIV/AIDS treatment programs:' Consequently, the percentage of women using contraceptives stagnated at 39 percent, according to the Kenya Demographic and Health Survey.

It's hardly surprising that contraceptive access is declining in Kenya, and there's more at work than simply a shift in funder priorities. One of the biggest family planning donors--the U.S.--is now putting tight strings on contraceptive aid through the application of the Bush Administration's so-called Global Gag Rule. The rules, in place under Presidents Reagan and Bush, suspended by the Clinton Administration, then promptly reinstated by George W. Bush--block nonprofit groups that provide abortion services from receiving U.S. family planning funds.

The Helms amendment to foreign assistance legislation, passed in 1973, already prevented federal money from paying for abortion services. But the Republican gag order does more, actually blocking any family planning assistance to any clinics that provide abortions or abortion counseling, even if those services are funded independently. There's no evidence that the policy has reduced the incidence of abortion (indeed, by denying women access to birth control it has probably increased them). The World Health Organization says that nearly 20 million unsafe abortions occur annually, mostly in developing countries. Those numbers will climb as reputable medical clinics are forced to choose between eliminating abortion services or risking all of their U.S. family planning aid.

In Kenya, U.S. policy almost certainly contributed to the spike in the birth rate. According to the Global Gag Rule Impact Project (GGRIP), a collaboration between Population Action International, Planned Parenthood Federation and others, Kenya's two largest providers (the Family Planning Association of Kenya and Marie Stopes International) refused as a matter of principle to sign onto the policy when it was reinstated in 2001. In doing so, they forfeited a considerable amount of U.S. Aid for International Development (USAID) family planning assistance, and many clinics were forced to dose. Often, these clinics were the only source of health care for Kenya's rural poor. GGRIP is working with a Kenyan researcher this fall to make the link between the Kenyan birth rate spike and U.S. policy more explicit.

Abortion is illegal in Kenya except to save the woman's life, but some 300,000 occur annually anyway (often without medical assistance) and contribute to the country's staggering number of maternal deaths--1,330 for every 100,000 live births. Today, half of all Kenyan women give birth before they're 20, and nearly half of all births are said to be unwanted or unplanned. Clearly, this is a country that would join the birth dearth trend if it could. But Kenya had 33.8 million people in 2005, and it could have 64 million by 2050 (up 92 percent).

A Selective Decline

It's hard to overstate the impact of Paul Ehrlich's book The Population Bomb in 1968. Ehrlich predicted, "The battle to feed all of humanity is over. In the 1970s and 1980s, hundreds of millions of people will starve to death in spite of any crash programs embarked upon now."

The population explosion was a popular topic of conversation in the late 1960s, even though the world then had only 3.5 billion people, slightly more than half what it has now. Ehrlich today acknowledges that he failed to see advances in farming that would enable much higher yields from finite resources, but he affirms his core point. "Since [1968] we've added another 2.8 billion--many more than the total population [two billion] when I was born in 1932," he says. "If that's not a population explosion, what is? My basic claims, and those of the many scientific colleagues who reviewed my work, were that population growth was a major problem." Many people think it still is, though they're having a harder time sounding the alarm.

Aside from having to dodge charges of racism as they criticize the U.S.'s high immigration levels, population activists are also often required to explain an increasingly complicated situation. Instead of one big explosion, rapid population growth is occurring in pockets around the world, surrounded by a sea of declining fertility. But when that fact is combined with the phenomenon known as "population momentum" (the tendency for numbers to keep increasing, even with lower fertility, because past baby booms created a very young population), it's still enough to add 80 million people a year to the planet's burden.

The UN now projects a world population of 9.1 billion (as the middle of three possible scenarios) in 2050. Where will that growth come from? Not from the industrialized countries, which are expected to have basically the same population they do today, 1.2 billion. But in the 50 least-developed countries, population will more than double, from 0.8 billion in 2005 to 1.7 billion in 2050. There are many Nigers and Kenyas, and they're still growing rapidly. The UN reports that Afghanistan, Burkina Faso, Burundi, Chad, the Democratic Republic of Congo, the Democratic Republic of Timor-Leste, Guinea-Bissau, Liberia, Mali, Niger and Uganda are all expected to triple in population by 2050.

Here's how some countries are affected by the birth dearth:

China. Despite a celebrated "one-child" policy, China's population of 1.3 billion still grows one percent per year, but it is slowing. The birth rate is now down to 1.6, which is sub-replacement level, but that hardly means that China is depopulating. In 2050, the UN says it is likely to have 1.4 billion people. Chinese population estimates are guesses; the country could have 1.5 billion people now, and consequently higher numbers at mid century, when it will finally start to see declining numbers.

India. By 2050, India will have far surpassed China as the world's most populous country. From 1.1 billion in 2005, it will likely grow to 1.6 billion by 2050. Demographer Carl Haub of the Population Reference Bureau points out that some of the poorest Indian states, including Uttar Pradesh and Bihar, have the population of medium-sized countries and are likely to get much bigger. The northern state of Uttar Pradesh, with high illiteracy levels, had 167 million people at the time of the 2001 census, and will soon reach 180 million. "Fertility declines there have been slow" Haub says. "Son preference is still very strong in the north, and it's one factor keeping the population high. Many families want two sons."

Pakistan. In 2006, the country's population was estimated at 166 million, but it is growing rapidly. Despite some signs of a birth-rate slowdown, it could nearly double to 295 million by 2050. Women in Pakistan still have an average of four children. The population is increasingly crowded into mega-cities Lahore and Karachi, which have some of the world's highest population densities.

Saudi Arabia. This country has some of the world's fastest population growth, with a birth rate of 4.5 (down from 5.7 in 2003). Its population is likely to more than double by 2050, from 24.6 million to 49.5 million. Saudi Arabia has a very young citizenry, with 43 percent under the age of 15--a factor that increases population momentum. Only 32 percent of married women use contraceptives, and abortion is illegal except for special cases.

Nigeria. Like Niger, Nigeria has a high birth rate, 5.9 in 2005. But unlike Niger, it is a large country, with 131 million people at the last census. And, again, it is expected to nearly double in size by 2050, to 258 million. Some 43 percent of the population is younger than 15. Life expectancy for men and women in Nigeria is just 44. A woman who gets an illegal abortion in Nigeria faces seven years in prison and the doctor faces 14, so the UN estimates that only 40 percent of the country's abortions are actually performed by doctors, or those with medical training. An estimated 366,000 unsafe abortions are estimated to occur annually in Nigeria. Maternal death in childbirth is quite common.

The scholars who study and publicize the birth dearth don't have much to say about continued population growth in the developing world. TV personality Ben Wattenberg (who coined the "birth dearth" phrase) is the author most recently of Fewer: How the New Demography of Depopulation Will Shape Our Future (Ivan R. Dee).

Wattenberg dismisses in an aside the plain fact that, despite declining fertility rates around the world, the momentum, or "push" factor, means that world population will likely grow to steeply before it subsides. He never mentions that human numbers more than doubled between 1950 and 2000.

While 44 percent of world population lives in countries with fertility rates at or below replacement level, the global average is still almost three children per woman--50 percent above replacement. The UN's median variant still projects above replacement-level fertility in 2050.

Wattenberg is distinctly selective with data, using a full page to show 63 countries with below-replacement-level fertility in 2000-2005, but no comparable chart on countries whose fertility is higher than replacement level. Today, 35 developing countries (30 of them "least developed") have birth rates that are above five children per woman.

"Ben Wattenberg and company seem to me to be deliberately ignoring that there are still almost 100 million births a year," says Alex Marshall of the UN Population Fund. And many of those births are occurring in the one world power that is experiencing a major population increase: the U.S. (see sidebar). The American population, growing one percent annually, is set to hit 300 million around the time this magazine is published. Although U.S. birth rates hover around replacement level, the country adds a legal immigrant every 31 seconds, or more than one million per year. Illegal immigration swells U.S. population much more, so that the 300 millionth American is more likely to move here than to be born here.

Celebrate or Mourn?

Mara Nelson, editor of Population Connection's magazine The Reporter, asks a very good question. If fertility rates are dropping around the world as women choose to have fewer children, why do commentators insist on calling it a crisis? She writes, "Fortunately, through hard work, devoted advocacy and intensive education efforts, population and health groups around the world have provided many people with the information and resources they need to take control of their own reproductive health.... [W]e're finally at a point where it's possible that a child born today will live to see the stabilization of world population:' And what's wrong with that?

Well, birth dearth alarmists say, the planet is depopulating and graying, and the implications of that are worse than if population growth were to continue. Cue Phillip Longman, author of The Empty Cradle: How Falling Birthrates Threaten World Prosperity and a Schwartz Senior Fellow at the New America Foundation. Longman has been finding a receptive audience for this message, delivered in his book, in articles in Foreign Policy and Foreign Affairs, and in lectures he delivers at such locations as the Long Now Foundation (which includes Whole Earth Catalog author Stewart Brand and musician Brian Eno as founding board members).

"An explosion in the world's elderly population, coupled with a dwindling supply of children and younger workers, threatens not only the global economy but also the global environment" he said in his Long Now talk in 2004. He notes that families embracing austere religious tenets--Hasidic Jews, fundamentalist Christians, Moslems, Mormons--are the ones having the babies today. "Unless secular societies take measures to increase the rewards of parenthood, and to better compensate those who are involved in nurturing and educating the next generation, we--and I mean the human race here--face a future dominated by fundamentalism" Longman said.

Longman may have a point there. Nancy Campbell, author of the 2003 book Be Fruitful and Multiply, says she'd like to see birth control less available so evangelical Christians will further populate the planet. "I think that Christian people, on the whole, are going to raise more God-fearing and honest citizens who will bless the nation" she says.

In an interview, Longman said that "the global trend is for fertility to decline everywhere, in Africa and the Middle East, too. It's not a phenomenon limited to the developed world" He said he was not aware of the birth rate stagnation in Kenya, which he attributed to "some blip that I'm not aware of." The big pattern, he said, is that people are "making the move out of the countryside, where children are an asset, to third world mega-cities, where they're a liability. They're also exposed to western media and the values that go with it, so it's no surprise."

But surely the rise of fundamentalist religions (which Longman cites) is sending a contrary message. In Salamatou Adamou's neighborhood in Limantchi, Niger, preacher El Hadj Sabiou emerges from his mosque to quote from the Koran, "To better propagate the faith, the Islamic Oumah [community] must procreate." Although birth rates are declining rapidly in some Arab countries, six of the 10 countries with the highest birth rates are Moslem. One in four of the world's population is Moslem today, but the faith's birth rate outstrips that of the world as a whole, and there are likely to be 1.89 billion adherents by 2025.

Longman points to significant declines in some Arab countries, notably Algeria, where the average woman had eight children in 1970. In recent years, however, fertility has fallen to replacement level and is staying there. Lebanese women had more than five children on average in 1970, but now their birth rate, too, has declined to below replacement. Iran has also fallen below two births per female, though a concentrated government effort that includes field officers bringing contraceptives to the rural poor is probably a significant factor there.

But statistics in other Moslem countries tell a different story. Saudi Arabia, which has eight times the population it had in 1950, is experiencing a slow decline, but is still growing rapidly, with a 4.09 fertility rate. The Occupied Palestinian Territory is at 5.57, more than double replacement level. In both places, the UN projects that replacement level will eventually be met (in Saudi Arabia's case, by 2035), though this is highly speculative.

No Easy Conclusions

It's easy to leave the impression, when talking about the world's falling birth rates, that world population is also declining. In the magazine Conservation in Practice, Longman writes that "world population growth has already slowed dramatically over the last generation and is heading on a course for absolute decline." That's true, but it gives the impression that a global decline in the number of people on Earth is just around the corner. But because of population momentum, it probably won't occur until 2050 at the earliest. And that UN projection is based on the assumption of today's fertility trends continuing nearly for the next several decades. (The UN also allows for the possibility that it will err on the low side, thus it also offers a "high variant" of a stunning 10.6 billion people in 2050.)

"It takes a generation for low fertility to transform into declining population because of momentum," says Thomas Buettner, chief of estimates and projections at the UN Population Division. "The world is like a supertanker that will go 20 miles before it stops. World population will continue to grow until 2050 at least, and it could climax as late as 2075" he adds.

Buettner says bluntly, "We are not now in a birth dearth scenario. World population is not declining. We have already more than six billion people on the Earth, and the next period will be characterized by continued population growth." Much depends on whether current trends will continue. Buettner says that if today's fertility rates, including the low rates in Europe and elsewhere, were kept constant for all countries, by 2050 the world would have 11.7 billion people. Nobody expects that to happen, but any number of factors could derail the steady declines seen in the last decades.

Haub of the Population Reference Bureau says to be careful of projected numbers. "When demographers make assumptions, that's exactly what they are" he says. "Extrapolating the European experience to every other region of the world--to expect that high-fertility African countries and Indian states have the fertility of Denmark, for instance--is really quite a stretch. The prospects for controlling population growth in Africa are not very good. More and more surveys show that fertility decline there is very slow among rural and very traditional populations. And governments are moving slowly, if at all." Africa is likely to add another billion people between now and 2050, growth that is not significantly slowed down by high MDS infection rates in some countries.

"The newspapers are full of stories about the birth dearth, but if you look at Latin America and Africa combined, they will add another 2.5 billion people in the next two decades" adds John Bongaarts, vice president of the policy research division at the New York-based Population Council. "In India and Bangladesh, women still want three kids, and they are having them. China will add another 200 to 300 million before its population peaks and India will add 500 million. People in China, India and other developing countries know how we live here in the U.S., and they want two cars and big houses also. That will cause massive strains on resources such as oil, and will contribute to global warming and local air pollution."

Bongaarts points out that Italy's low birth rate will result in it having, 20 years from now, the same population it had in the 1960s, "and no one was saying that was a crisis back then." He acknowledges a significant difference, however: Italy will have the same population, but it will be much older, straining health care systems and pension programs. One solution may be to allow Italians to retire later, but there's no denying that a problem exists.

Will the graying population lead to "a new Dark Ages," as Longman predicts, even if the dependent population grows larger than the pool of working-age people? It's impossible to say, but with continued population growth and unfolding global warming putting a strain on world food and resource supplies, we probably have more immediate problems than that.

Brian Dixon, a spokesperson for Population Connection, ticks off climate change and access to safe drinking water as the most serious issues facing the planet. He cites the case of the Nile River, which has three bordering countries--Egypt, Sudan and Ethiopia--all dependent on its finite resources. All three are likely to double their populations in 30 years. "We believe that the consequences of a rapidly growing population are much more serious than problems of declining population growth rates," Dixon says.

Engelman of Population Growth International agrees. "The problems associated with the birth dearth are fewer than the benefits that will accrue," he says. "It's very helpful for resolving the environmental problems we face. Some countries will face challenges to their social security and pension systems, but there's no compelling evidence it will cause a disaster. Russia's life expectancy has declined significantly, but it's not just because of lower birth rates. There are also higher death rates, partly from AIDS. That's a tragedy to be concerned about, and more so than the loss of population resulting from women making their own decisions to have fewer children."

"The key to all this is what are women's intentions of childbirth?" Engelman says. "It's not up to demographers. What we're seeing is good results from women in the developed world succeeding at their own derisions, so what could be better? But surveys across Africa show that women there are still having more children than they actually desire, and maybe a third to a quarter of pregnancies are not intended. There is still a high unmet need for family planning."

John Seager, executive director of Population Connection, points out that alarmism over a graying population and the death of Social Security is probably unwarranted, since with replacement-level fertility the U.S. will not run out of payees anytime soon. And an aging population offers financial advantages as well as challenges: more life-care communities supported with taxpayer funds, but fewer expensive elementary schools built with that same money.

Japan, with a total fertility rate of only 1.4 (and a possible loss of 27 million people by 2050), is experiencing a flourishing economy characterized by the fastest growth among major industrial powers. "The Japanese economy for the first time in 15 years is getting up off the mat," says Carl Steidtmann, chief economist with Deloitte Research.

Instead of despairing, Seager thinks we should see unprecedented opportunity. "The possibility of a less-crowded world is no cause for anxiety, let alone panic," he writes. "It's no nightmare. Rather, it's an achievable dream worth all of our efforts." CONTACT: Population Action International, [phone], www.populationaction.org; Population Connection, [phone], www.populationconnection.org; Population Reference Bureau, [phone], www.prb.org.

RELATED ARTICLE: The planet's lopsided growth.

In mid-2005, women around the world had an average of 2.7 children, according to the Population Reference Bureau. That seven-tenths of a percentage point above replacement level may not seem like a lot, but it is contributing to a dramatic population expansion, from 6.4 to 9.2 billion, between now and 2050.

Let's look at the accelerating momentum of population growth. In the year 1000, there were an estimated 254 to 345 million people on the planet, mostly living agrarian lives. World population grew very slowly in those days. In 1200, 200 years later, there were still only 360 to 450 million people. Move all the way up to the relatively modern world, in 1700, and there were still only 600 to 679 million people sharing the planet.

The first billion was reached, probably, in 1802. But after that we really took off as a species. It took just 125 years to add the second billion, in 1927, and only 34 years to get to three billion, in 1961. Four billion (1974) took just 13 years, and five billion (1987) another 13. We crossed the six billion threshold in 1999, after only 12 years. When will we get to seven billion? How does 2012, just six years away, sound?

If you were to chart human population growth between 1950 and what is projected for 2010, it would look like a steady, unbroken ascent, with no interruption from the birth dearth. This is true despite the fact that the growth rate peaked in the mid-1960s, at 2.2 percent per year (it is now 1.3 percent). World baby booms from that period are still having an effect, leading to a large population of women in their child-bearing years, and thus continued growth. And that growth will continue for several decades more.

The population is growing, but the growth is very uneven. Here's one way of looking at it: in 1970, Europe had 655 million people. In 2050, it will have ... 653 million, which means that zero population growth has arrived there. Africa had 357 million in 1970, but it will have 1.8 billion in 2050. Asia, similarly, goes from 2.1 billion to 5.7 billion in that period. That's a huge redistribution of world population. If you took a snapshot today and reduced the population to 100 people, 57 would be Asian, 21 European and eight African. But that ratio is certain to be dramatically different 50 years hence.

Any look at future population is guesswork, and the world's principal demographer, the United Nations, admits as much. Its projections see almost every country in the world headed toward below replacement-level fertility, which will certainly lead to a birth dearth. "Total fertility in high-fertility and medium-fertility countries is assumed to converge eventually toward a level of 1.85 children," says the UN Population Division.

But are the world's high-fertility countries, in Africa, South Asia and the Middle East, really going to experience such dramatic drops in their birth rates? Will, for example, Mali, with a birth rate of 7.1 today, eventually start to look like Poland, where it is 1.2? Population Action International is skeptical. "Poor access to family planning and the low social status of women continue to drive high rates of population growth in most of sub-Saharan Africa, in many countries of the Middle East and in parts of South Asia," says the group. "In many of these countries, most couples still want large families, in part to offset continuing high infant mortality."

Even if the rates do decline, actual numbers will probably continue to go up. Thomas Buettner, the UN's chief of estimates and projections, notes that in some African countries, 50 percent of the population is below 16 years old, so even if these emerging adults have fewer children than their parents, their countries will continue to grow.

Demography is hardly an exact science. "Anytime you project population ahead 50 years, it's a wild guess," says Jeff McNicoll, a senior associate at the Population Council. "The UN is modeling its projections for the less-developed countries on what has happened in other parts of the world. In Africa, what will happen is highly contingent on economic and political developments." Indeed. CONTACT: Population Council, [phone], www.popcouncil.org.--Jim Motavalli

RELATED ARTICLE: The U.S.: a population-environment imbalance.

The U.S. is the only industrialized nation with significant population growth, and a new report sees those burgeoning numbers as a factor in our unparalleled impact on the environment.

While Europe shrinks, U.S. population grows by just under one percent a year, which translates to 8,000 people a day, or three million per year. The 300 millionth American will either be born here (or move here) sometime this fall. According to Victoria Markham, executive director of the Connecticut-based Center for Environment and Population (CEP), the growth is magnified by a very high rate of resource consumption. "The U.S. has the largest per-capita environmental impact in the world," she says, "not only in terms of resource use, but also the pollution and waste associated with it."

The U.S. uses three times more water than the world average per capita, and (despite being only five percent of world population) consumes a quarter of its energy. Americans buy and use a lot of stuff, Markham says, but there's more to it than that. Baby boomers, despite their relatively high level of environmental awareness, are also enjoying an unprecedented amount of wealth, living in larger houses on more land than any other generation in U.S. history. What's more, she says, the nation's number of households is also increasing dramatically as families fragment. (Average household size dropped from 3.1 persons in 1970 to 2.6 in 2000, according to U.S. Census figures.)

In what Markham calls an "aha moment," the CEP report also found that the southern and western U.S. are "population-environmental hot spots." They are leading the nation in per capita energy and water use, with not only the largest number of people but also the fastest rate of growth. The top 10 states for biodiversity risk are all in the two regions.

The U.S. has doubled in population since 1950, and is the third most populous country in the world. Increasing our burden on the land, American settlement patterns are very lopsided. Over half of U.S. population is in the south or west (although the Northeast remains the most densely populated region). Half of all Americans live within 50 miles of a coast, on just a fifth of the country's land area. Only three percent of the population lives in the 10 least populated states.

Immigration accounts for 40 percent of U.S. population growth, CEP estimates, and California is a prime destination for immigrants. It's not surprising, then, that the state added more than two million people between 1990 and 2000. But natural population growth is also higher in the U.S. than it is virtually anywhere else in the industrialized world. CONTACT: Center for Environment and Population, [phone], www.cepnet.org.--J.M.

JIM MOTAVALLI is editor of E.