Showing posts from category Japan.
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How Did We Arrive at 7 Billion – and Where Do We Go From Here? [Part One]
›October 26, 2011 // By Elizabeth Leahy MadsenThe United Nations Population Division has estimated world population will reach seven billion on Monday. Which changes in demographic trends led us to this milestone? What do the past and present tell us about how human numbers will change in the future?
The “Day of Seven Billion” was announced this spring following the release of the latest revision of UN population projections. Although the seven billionth person will not be precisely identified, this estimate is based on careful demographic modeling. Every two years, the UN revises its projections to incorporate the latest trend data and modify its assumptions, as seemingly small changes can make a huge difference demographically.The UN estimates that the seven billionth person alive today will be born on October 31. Demographer Elizabeth Leahy Madsen explains how we got to that number, its significance, and where our demographic path might take us from here. Read part two here.
The United Nations Population Division has estimated world population will reach seven billion on Monday. Which changes in demographic trends led us to this milestone? What do the past and present tell us about how human numbers will change in the future?
The “Day of Seven Billion” was announced this spring following the release of the latest revision of UN population projections. Although the seven billionth person will not be precisely identified, this estimate is based on careful demographic modeling. Every two years, the UN revises its projections to incorporate the latest trend data and modify its assumptions, as seemingly small changes can make a huge difference demographically.
Demography Is Driven by Fertility and Population Momentum
Since world population reached three billion in 1959, the rate of growth has increased, peaked, and begun to slow. Each succeeding milestone was reached more quickly than the last: It took 15 years to reach four billion, 13 years to hit five billion, and only 11 years to get to six billion at the end of 1998. The interval leading to seven billion was slightly longer, at 13 years, as the global rate of population growth has slowed.
Although mortality and migration also affect population trends, the factor with the greatest influence by far is fertility – the average number of children born to each woman. The decline in the global fertility rate from an average of nearly 5 children per woman in the early 1960s to 2.5 children today has in turn slowed the pace of world population growth. However, demographic momentum from previous generations of high fertility can drive population growth for decades to come. Even if Nigeria reached replacement-level fertility today, its population would still grow by one-third by 2050 as the number of births continued to exceed the number of deaths.
Assumptions Matter
Population projections consider: 1) current data about fertility and 2) assumptions about the ways fertility will change in the future. These assumptions vary depending on the source, so how much of a difference do they make? As it turns out, quite a lot.
Projections of world population in 2050 range from 8.1 billion (if fertility rates fall to a global average of 1.7 children per woman) to 10.9 billion (if they remain unchanged). The gap of nearly three billion between those possibilities is greater than the combined populations of China and India today.
Estimates vary even more widely for the end of the century, with the UN projecting that by 2100 world population could total anywhere between 6 billion (if total fertility falls to an average of 1.55 children per woman) and 27 billion (if every country’s fertility rates remain constant at today’s levels).
While demographers parse the details of the projections, policymakers would like to know which of these scenarios is more likely. After all, the economic, environmental, and political consequences of a population of 8 or 11 billion two generations hence are not the same, and a world of 27 billion is difficult for anyone to fathom.
If we simply projected past trends into the future at a steady rate, the population estimates on the low end of the fertility spectrum seem more likely. The global fertility rate has fallen from 4.5 children per woman in the early 1970s to 2.5 today, a decline of 43 percent, so the 14 percent decline projected in the medium-fertility variant between now and 2050 seems reasonable at first glance, perhaps even conservative. The medium-fertility variant assumes that all countries’ fertility rates will begin moving towards replacement level, around 2.1 children per woman, regardless of whether they are currently above or below that number.
However, even a 14 percent decline in fertility assumes that areas where fertility rates remain stalled at high levels will soon begin rapid declines, paralleling the past experience of other regions. As Population Reference Bureau demographer Carl Haub writes, “the assumption that the developing world will necessarily follow the path of the industrialized world…is far from a sure bet.”
In the last 40 years, fertility rates in the Caribbean, northern and southern Africa, Latin America, and all of Asia declined by 50 percent or more. The pace of decline in sub-Saharan Africa, while still notable, was much slower, at 23 percent. In order to meet the UN medium-variant projections, the region’s fertility rate would need to fall by nearly 40 percent by mid-century.
Some of the largest, fastest-growing populations in the developing world would need to experience a major acceleration from recent trends. In Nigeria, fertility edged down by 15 percent between 1970 and 2010, but the medium variant projection depends on a decline of 37 percent over the next four decades; Ethiopia’s fertility rate will need to fall by half.
Gender Matters, Too
The great irony of fertility trends is that gender inequities play an important role at both ends of the scale. In countries with the highest fertility rates, women tend to have less education than men and less autonomy. Their fertility choices may be greatly affected by the preferences of their husbands or other family members. In Niger, which has the highest fertility rate in the world, married men would, on average, like three more children than married women. In Uganda, where women average more than six children each, 60 percent of men report that domestic violence is justified.
By contrast, in countries with the lowest fertility rates, women have achieved equal access to education and the labor market, with more autonomy about how to earn income and what to do with it. Yet cultural expectations that place the burden for child and elder care and housework almost entirely on women can make marriage an unappealing option. In Japan, which is among the 10 lowest fertility countries in the world, more women are choosing to stay single: The marriage rate has fallen by almost half since the 1970s. Japanese women who do marry are waiting until their late 20s and tend not to give birth until they are 30, both of which result in lower average family size.
Even at this end of the demographic spectrum, the assumptions embedded within population projections seem optimistic. Japan’s fertility rate was last above replacement level in the early 1970s; it has fallen steadily to 1.3 children per woman today. The UN projections assume that fertility will immediately reverse track and begin rising to over 1.8 children per woman in 2050, rebounding above two children per woman before the end of the century.
The stalled high fertility rates in much of sub-Saharan Africa and parts of the Middle East, together with unprecedented low fertility in Eastern Europe and parts of East Asia, indicate that we are currently in an era of remarkable demographic diversity, despite the UN’s projection of future convergence.
Continue reading part two here.
Elizabeth Leahy Madsen is a consultant on political demography for the Wilson Center’s Environmental Change and Security Program and former senior research associate at Population Action International.
Sources: Boling (2008), Haub (2011), Japan Statistics Bureau, Measure DHS, UN Population Division, UN Population Fund, Washington Post.
Image Credit: Chart data from UN Population Division, arranged by Elizabeth Leahy Madsen. -
Rare Earths No More? Mineral Discoveries a Potential Game-Changer for East Asia
›July 7, 2011 // By Schuyler NullDiscoveries announced in a journal article over the weekend may prove a game-changer for global rare earth supplies and recent diplomatic maneuvering in East Asia between China, Japan, Vietnam, and the United States. A team of researchers from Japan’s Agency for Marine-Earth Science and Technology published findings in Nature Geoscience that indicate vast underwater reserves of rare earth minerals are scattered across a huge swath of the Pacific, including south and east of Japan. The U.S. Geological survey estimates current global reserves of rare earth minerals at about 110 million tons; Yasuhiro Kato, the lead author of the Japanese team, told Reuters that the sites surveyed could contain an additional 80 to 100 billion metric tons (yes, with a “b”) of the valuable resources.
The authors write that an “area of just one square kilometer, surrounding one of the sampling sites, could provide one-fifth of the current annual world consumption of these elements.” The team collected data from 78 sites in total, with the largest concentrations centered east of the Hawaiian and Polynesian islands (see a map of the surveyed areas here).
Resource Relationships
The discovery could prove crucial for Japan, as it has been seeking alternative sources of rare earth minerals after an embargo earlier this year by China, which controls 97 percent of the world’s current supply. The embargo (which China denied) was imposed in October of last year after the Japanese navy arrested the captain of a Chinese fishing boat, which was alleged to be encroaching on Japanese territorial waters. China’s response increased tensions across the region and produced a flurry of warnings in Washington over the security of U.S. supplies.
Although the embargo was later lifted, Japan and Vietnam reached an agreement for development of Vietnamese mines in November. The tensions sparked by the encounter also spread to the South China Sea where Chinese, Vietnamese, and Filipino forces have stepped up their jockeying over disputed and resource-rich waters to the highest levels in years. Vietnamese and Chinese naval forces recently held mirror exercises, and Filipino officials invoked a 1950-era defense pact with the United States. Chinese Vice Foreign Minister Cui Tiankai told reporters in June: “I believe the individual countries are actually playing with fire, and I hope the fire will not be drawn to the United States.”
Secretary of State Hillary Clinton called concerns over navigability and Chinese insistence on bilateral (as opposed to multilateral) negotiations in the South China Sea a matter of “national interest” for the United States last year.
The Japanese team’s discovery has the potential to significantly impact the power dynamics behind these tensions. China has used its rare earth monopoly to pressure Japan and the United States, which in turn may have also helped embolden its recent more aggressive maritime policies. If the new rare earth discoveries prove viable, that calculus could change considerably.However serious questions remain: Many of the discoveries lie outside of established exclusive economic zones, so who has the rights to mine them? They’re also between 11,500 and 20,000 feet below the surface – how long before we have the technologies to extract them at an industrial scale? And how safe – both for humans and the environment – will those processes be? Aboveground rare earth mines are some of the most damaging to the environment – part of the claimed reason China curbed overall exports earlier this year, which drove up global prices and drew the ire of the World Trade Organization.
For more on the importance of rare earth minerals to the defense and electronics industries, see New Security Beat’s “Rare Earth: A New Roadblock for Sustainable Energy?” and “Reading Radar: The Mineral Security of the United States.” For more on the exclusive economic zones map, see “Eye on Environmental Security: Natural Resource Frontiers at Sea;” and on the South China Sea and what it reveals about future diplomatic fault lines between the United States and China, see “U.S. v. China: The Global Battle for Hearts Minds and Resources.”
Sources: Asia Sentinel, The Atlantic, BBC, Government Accounting Office, Nature Geoscience, The New York Times, Reuters, Tech News Daily, U.S. Department of State.
Photo Credit: Adapted from “USS Mustin underway in the Pacific Ocean,” courtesy of flickr user Official U.S. Navy Imagery, and “Exclusive Economic Zone,” used with permission courtesy of Theo Deutinger and TD Architects. -
Ten Billion: UN Updates Population Projections, Assumptions on Peak Growth Shattered
›May 12, 2011 // By Schuyler NullThe numbers are up: The latest projections from the UN Population Division estimate that world population will reach 9.3 billion by 2050 – a slight bump up from the previous estimate of 9.1 billion. The most interesting change however is that the UN has extended its projection timeline to 2100, and the picture at the end of the century is of a very different world. As opposed to previous estimates, the world’s population is not expected to stabilize in the 2050s, instead rising past 10.1 billion by the end of the century, using the UN’s medium variant model.
