• 7 billion people? How do they know?

    Daniel Mihailescu / AFP - Getty Images

    A counter approaches the 7 billion mark at a National Geographic exhibit in a subway station in Bucharest, Romania, highlighting global population density.

    By Alan Boyle, Science Editor, NBC News

    Head-counters around the world are marking Monday as the day when the world's population hits the 7 billion mark. It's a date that has served as the focus for musings on the problems and possibilities facing our species and our planet. But how do experts know that Oct. 31 is the precise day that the world's 7 billionth human being will be born?

    "The answer is, we don't," said Omar Gharzeddine, a spokesman for the U.N. Population Fund. Even though the United Nations gathered the statistics pointing to the Day of 7 Billion, U.N. officials freely admit that Oct. 31 is merely the date that popped out of their population projections, and will serve as a symbolic rather than a statistically precise milestone.

    Every five years, the U.N.'s Population Division updates its country-by-country projections of demographic trends, and the computer models for 2010 were combined to yield a projection of Oct. 31. In the report, World Population Prospects, the U.N. analysts emphasize that there could be a 1 to 2 percent overall margin of error in the global tally, which translates into plus or minus six months or more for reaching the 7 billion mark.

    Some folks are planning to identify a specific baby in India's Uttar Pradesh state or Russia's Kaliningrad region as the 7 billionth human on the planet, but Gharzeddine told me that the United Nations isn't giving official status to such publicity efforts. "There's no way that the U.N. or anyone could know where or at what minute on the 31st the 7 billionth baby will be born," he said.

    The Day of 7 Billion could well be revised, even years later. That was the case for the Day of 6 Billion, Gharzeddine pointed out. "The U.N. marked the '6 billionth' [person] in 1999, and then a couple of years later the Population Division itself reassessed its calculations and said, actually, no, it was in 1998," he told me.

    This time around, a lot of population experts suspect that we're actually months away from hitting the 7 billion mark. The U.S. Census Bureau, for example, projects that the milestone won't be reached until March 12, 2012. And researchers at the International Institute for Applied Systems Analysis point to a time frame between February 2012 and July 2014.

    Those same researchers say that the tally for the world's total population is "not the issue" that experts should be worrying about. Instead, they say the United Nations and other groups involved in global development should focus on imbalances in the distribution of various populations by age, education and health status.

    Gharzeddine agreed that population policy should be about more than the big number. "It's a good occasion to highlight all these issues," he said. Among the issues on his list:

    An estimated 1.8 billion people are between 10 and 24 years of age, meaning that this is the biggest generation of young people in history. But 90 percent of those youths live in the developing world and are in danger of missing out on the economic opportunities of the 21st century.  

    About 215 million women live in areas of the world where access to family planning and contraception is restricted. That's one of the factors between the wide disparity in fertility rates, which range from 1.6 births per woman in east Asia to five births per woman in some parts of Africa.

    What does the future hold? It's taken 13 years to go from 6 billion to 7 billion, but the United Nations estimates that we'll hit 8 billion by 2023, 9 billion by 2041 and 10 billion at some point after 2081. If you think there's a lot of uncertainty surrounding the Day of 7 Billion, hold onto your hats: Relatively small increases in fertility rates could cause a doubling of the current population by 2100 (to 15.8 billion), while a small decrease could result in fewer people than we have today (6.2 billion by 2100).

    More about global demographics:

    For more about the Day of 7 Billion, click on over to the U.N. Population Fund, 7 Billion Actions and the 7 Billionth Person Project.

    Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding me to your Google+ circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

     

  • 'Typical face' is Chinese ... for now

    By Alan Boyle, Science Editor, NBC News

    Based on the world's demographics, the typical human is a 28-year-old Chinese man — but humanity's most common face could be radically different in just 20 years' time.

    The "typical face" of our species was unveiled this week in the National Geographic video below, and it's featured as well in a poster supplement in the March issue of National Geographic magazine. The typicality project is part of a special report on global human population, which is expected to hit 7 billion by the end of this year.

    So how do you judge typical, and why does the "typical human" look the way he does? For National Geographic, the yardsticks have to do with averages and pluralities.

    For example, the world population's average age is 28, which is factored into the face's look. There are slightly more men than women on Earth, which is why the "typical" human is male. And the world's largest ethnic group is Han Chinese, making up an estimated 1.1 billion of the global population, which is why the magazine's editors went with an Asian look.

    As for the specific look of that face, that's based on an visual averaging process conducted by the Chinese Academy of Sciences, which can draw upon tens of thousands of face photographs collected for a variety of databases over the past decade. One of these databases is part of a long-range study on face-recognition software for Asian ethnic groups. (Which sounds slightly scary.)

    The fuzzy, averaged-out image was passed along to digital artist Joe Lertola of Bryan Christie Design, who re-created the face photo for National Geographic's poster using 7,000 computer-generated human figures. An interactive graphic on National Geographic's website provides more detail about the creation of the face and lets you zoom in on the composite image.

    Here are a few more factoids about the typical human:

    • He's right-handed, because more people are righties than lefties.
    • He makes less than $12,000 a year, in line with the world's average income.
    • He doesn't have a bank account, but he does have a cell phone. 

    Because National Geographic defines its typical ethnic group as the biggest plurality in the world population, that ethnicity could change over time — and in fact, the population of India is projected to surpass the Chinese population by 2030. At that time, India is expected to have more than 1.53 billion people, while China is expected to reach its peak population of 1.46 billion and begin a slow decline. By 2030, the total tally of the world's population will be well on its way to a projected peak of 9 billion or more.

    If current trends hold true, the generic face of humanity will eventually be Indian, not Chinese. And there may be more changes in store as global population shifts. Isn't that just typical?

    Update for 12:30 a.m. ET March 5: A lot of the commenters are wondering whether it's really fair to use an all-Chinese face as a symbol for the world's entire population — and John Tomanio, senior graphics editor for National Geographic magazine, agreed that the concept is open to debate.

    "There are many ways to define 'typical,' that's true," he told me in a follow-up phone call. The decision to go with an average Chinese face was based on the idea that the world's "largest ethnic group was Han Chinese."

    "We didn't mean it to be provocative," Tomanio said. "But afterward we realized, 'OK, people might want to talk about this.'" Which is fine with him. So feel free to talk about this in the comment section below, but please take the high road rather than the low road in your discussion. The Cosmic Log community has a reputation to uphold.  ;-)

    More on population:

    Join the Cosmic Log community by clicking the "like" button on our Facebook page or by following msnbc.com science editor Alan Boyle as b0yle on Twitter. To learn more about Alan Boyle's book on Pluto and the search for planets, check out the website for "The Case for Pluto." 

  • Worries about the world in 2050

    How populous could Earth become? Some experts project that the peak population will hit 9 billion in the year 2050.

    By Alan Boyle, Science Editor, NBC News

    Some futurists predict that the next few decades will bring about wondrous revolutions in genetics and robotics, leading to resolutions of all the problems that afflict us today. But what if those revolutions don't work?

    The darker visions for the next 40 years — widespread food and water shortages, a proliferation of failed governments, millions of "environmental refugees" fleeing to northern countries — came into the spotlight over the weekend at the annual meeting of the American Association for the Advancement of Science in Washington.

    The year 2050 was the focus for the debate, because that's when experts have projected that the world's population will top out at 9 billion people. The big question is, how much heartache will humanity have to go through by the time it gets to 2050?

    Unless current trends change, "by 2050 we will not have a planet left that is recognizable," said Jason Clay, the World Wildlife Fund's senior vice president for market transformation.

    "If we don't get food right — where we produce it, and how we produce it — we can simply turn off the lights and go home," Clay told reporters.

    Food issues on the rise
    So what's not right about food? Based on an analysis of Earth's resources, our planet should be able to sustain 11 billion people on a vegetarian diet, said Joel Cohen, a population expert at the Rockefeller University. But among the current population of 7 billion, "a billion of those are hungry" already, he said. One of the reasons he sees is that humans are sharing their agricultural grains with livestock as well as machines (in the form of feedstock for biofuel conversion).

    "We're using less than half of the cereal we grow to feed humans," Cohen said.

    African countries are expected to be flashpoints for future flare-ups involving food shortages and populations on the rise, but if climate change continues on its current track, that could bring about an increasingly international crisis. Cristina Tirado, a public health expert at the University of California at Los Angeles, said the United Nations has projected the northward movement of 50 million "environmental refugees" by the year 2020, due to the negative effects of climate change on food security.

    "When people are not living in sustainable conditions, they migrate," she explained.

    There's already an increased influx of migrants from Africa to southern Europe — and Clay said he expected to see three or four "failed states due to food prices." You could argue that such a failure has taken place already, in the form of the Tunisian government's recent fall.

    "Most of the conflict is going to be domestic," Clay said. "I don't think it's going to be international for a while."

    The food fix?
    So what is to be done? Clay said one part of the equation is to get serious about reforming agriculture, on a scale at least as big as the "green revolution" of the 1960s. "What we need to do is freeze the footprint of food — and then make [agriculture] more efficient," he said.

    That means reducing the greenhouse-gas footprint of the agricultural production cycle, and it also means trimming back on the amount of energy, fertilizer and irrigation required to grow crops. The experts also said the shift toward converting food (such as corn) into biofuel should be reversed.

    That's just one side of the equation, however. The solution also has to include methods to slow down population growth, such as family planning education in the developing world. John Casterline, director of the Initiative in Population Research at Ohio State University, said there are "high levels of unmet need for family planning" around the world. He cited figures indicating that one-fifth of married women in the developing world have unintended pregnancies, a proportion that goes up to a fourth in sub-Saharan Africa.

    The idea of funding international family planning programs has been controversial in the United States, but the experts voiced hope that such efforts would gain more support as the planet rolls toward 2050.

    Casterline noted that the best antidote to overpopulation woes appeared to be economic stability rather than misery. "It looks like when things get better, families get smaller," he told me.

    Will things get better between now and 2050? Optimists such as inventor/futurist Ray Kurzweil are betting that rapidly accelerating technology will save us, but the population experts say their projections have to account for many factors, including advances in dealing with aging. If the average life expectancy heads toward 100 years by the year 2100, as some project, that would make for a more complicated century. The Population Council's John Bongaarts said some of the forecasts call for a peak population of as much as 13 billion.

    "If I had to bet, I would bet on nine and a half billion by 2075," Bongaarts said.

    How do you feel about the world in 2050 ... or 2075, for that matter? Optimistic or pessimistic? Weigh in with your comments below.

    More on population policy:

    Join the Cosmic Log community by clicking the "like" button on our Facebook page or by following msnbc.com science editor Alan Boyle as b0yle on Twitter. To learn more about Alan Boyle's book on Pluto and the search for planets, check out the website for "The Case for Pluto."