Global Warming: New Scenarios from the Intergovernmental Panel on Climate Change

The Intergovernmental Panel on Climate Change (IPCC) was set up in 1988 by the World Meteorological Organization and the United Nations Environment Programme to review the state of knowledge about human‐induced climate change and assess possible responses. Most of its activities are conducted by three working groups, concerned respectively with scientific aspects of the climate system, with the vulnerability of human and natural systems to climate change, and with options for mitigating that change. The major IPCC reports have been highly detailed statements of scientific consensus on changes in the climate system, issued at roughly five‐year intervals. These reflect the input of some hundreds of scientists, with drafts scrutinized by expert reviewers, revised to attain consensus, and eventually approved (or “accepted”) by the full Panel. The first such assessment, published in 1990, was influential in formulating the Framework Convention on Climate Change adopted at the 1992 Rio conference. The second assessment report (SAR), Climate Change 1995, produced the widely cited estimate that global warming would raise average temperatures by 1°–3.5°C by 2100, with a “best estimate” of 2°C, and produce a sea‐level rise of 0.13 – 0.94 meters. That report took the further step of explicitly linking the warming to anthropogenic (human‐caused) emissions of greenhouse gases. Its cautious conclusion: “The balance of evidence suggests a discernible human influence on global climate.” Climate Change 2001: The Scientific Basis is Working Group I's contribution to the third IPCC assessment. The document was finalized at the Group's meeting in Shanghai in January 2001. A brief (18‐page) “Summary for Policymakers” was also released at this meeting, distilling the findings of the full report and putting them in more accessible language. Two sections of this summary document, presenting the Group's projections of atmospheric temperature trends and sea‐level rises, are reproduced below. The procedure followed was to assemble hypothetical alternative combinations of future greenhouse gas emissions in the form of emission scenarios, which were fed into large‐scale climate models to produce estimates of future temperature and sea‐level trends. For the third assessment report the scenarios used were set out in the IPCC Working Group Ill's Special Report on Emission Scenarios (March 2000), and are referred to below as the “SRES scenarios.” There are 35 of them in all. They fall into six groups, detailed in the text box, from each of which an illustrative case is plotted in the charts. (The shaded areas in the charts are envelopes spanning the 35 scenarios. Some additional details shown in the original charts have been omitted here for clarity.) The SAR scenarios are referred to as IS92. The major difference from the second assessment is in the projected temperature increase, which is now put at 1.4°–5.8°C (or in Fahrenheit degrees, 2.5°–10.4°). The projected sea‐level rise is slightly smaller, at 0.09 – 0.88 meters. There is also a strengthening of the statement on anthropogenic causes, which now reads: “There is new and stronger evidence that most of the [atmospheric] warming observed over the last 50 years is attributable to human activities.” The report notes that even with stabilization of greenhouse gas emissions, there may be continuing climate effects beyond the twenty‐first century. One such effect is the “weakening of ocean thermohaline circulation “—the ocean currents that, for example, transport heat into high northern‐hemisphere latitudes and moderate the coastal climates of those regions. The summary report is available online at the IPCC's website, www.ipcc.ch . The complete third assessment report, covering also the conclusions of Working Groups II and III (particularly on the social and economic costs of forecast climate change), will be released shortly.     

How do Recent Population Trends Matter to Climate Change?

Although integrated assessment models (IAM) of the Intergovernmental Panel on Climate Change (IPCC) consider population as one of the root causes of greenhouse gas emissions, how population dynamics affect climate change is still under debate. Population is rarely mentioned in policy debates on climate change. Studies in the past decade have added significantly to understanding the mechanisms and complexity of population and climate interactions. In addition to the growth of total population size, research shows that changes in population composition (i.e. age, urban–rural residence, and household structure) generate substantial effects on the climate system. Moreover, studies by the impact, vulnerability and adaptation (IAV) community also reveal that population dynamics are critical in the near term for building climate change resilience and within adaptation strategies. This paper explores how global population dynamics affect carbon emissions and climate systems, how recent demographic trends matter to worldwide efforts to adapt to climate change, and how population policies could make differences for climate change mitigation and adaptation.     

Demographic aspects of climate change mitigation and adaptation

This paper addresses the contribution of changes in population size and structures to greenhouse gas emissions and to the capacity to adapt to climate change. The paper goes beyond the conventional focus on the changing composition by age and sex. It does so by addressing explicitly the changing composition of the population by level of educational attainment, taking into account new evidence about the effect of educational attainment in reducing significantly the vulnerability of populations to climatic challenges. This evidence, which has inspired a new generation of socio-economic climate change scenarios, is summarized. While the earlier IPCC-SRES (Intergovernmental Panel on Climate Change—Special Report on Emissions Scenarios) scenarios only included alternative trajectories for total population size (treating population essentially as a scaling parameter), the Shared Socio-economic Pathways (SSPs) in the new scenarios were designed to capture the socio-economic challenges to climate change mitigation and adaptation, and include full age, sex, and education details for all countries.     

Globalization and Inequality: A Norwegian Report

Is global inequality increasing? Some authoritative voices—for example, from the United Nations Development Programme—assert unequivocally that it is, and have carried popular belief with them. Others see a more nuanced and on balance a positive picture. Any attempt to answer the question must grapple with many conceptual and measurement difficulties. These are not wholly eliminated even if the inequality in question is narrowed to that among the per capita incomes of countries, ignoring intracountry differences in income. Disagreement about the empirical record has not impeded argument over causes. Globalization—the expansion of trade, investment, and technology flows among states that is making for a more integrated world economy—is invoked on both sides: seen by some as further marginalizing the world's poor, by others as offering a route out of poverty. The starkly different positions surface in the heated debates that have surrounded the World Trade Organization and the proposal for a Multilateral Agreement on Investment. The nature of trends in international inequality and the role in them of globalization are explored in a recent report issued by the Norwegian Ministry of Foreign Affairs, Globalisation and Inequality: World Income Distribution and Living Standards, 1960–1998 (October 2000), the summary from which is reproduced below. The report finds that global inequality between countries has decreased over the last four decades. Globalization may or may not have contributed to that outcome, but at least does not appear to work against it. In sum, “not everything has turned out badly; in fact there has—in spite of the setbacks in some regions and in spite of population growth—been considerable global progress during the last decades.” Given the chosen focus on inequality, there is little discussion in the report of that other dimension of global progress: changes in absolute income levels. But in assessing the implications of development for human welfare, the issue of economic growth and its relationship to globalization is clearly pertinent. Footnote 4 offers a passing glimpse of that dimension, referring to changes in absolute poverty. The World Bank's World Development Report 2000/2001 estimates that the number of people in absolute poverty (living on less than $1 a day) changed little between 1987 and 1998: it went from 1.18 billion to 1.20 billion. As the population grew, this meant a modest reduction in the proportion in absolute poverty in the world population (excluding the rich countries): from 28.3 percent to 24.0 percent. But in the East Asia and Pacific region—a region characterized by both rapid overall economic growth and increasing integration into the global economy—the number of poor dropped from 418 million to 278 million during the same period, with the proportion dropping from 26.6 percent to 15.3 percent. The report was commissioned from the Norwegian Institute of International Affairs (NUPI), and prepared by Ame Melchior, Kjetil Telle. and Henrik Wiig. It is available online both in its English version and in its original (and longer) Norwegian version—the former at http://odin.dep.no/ud/engelsk/publ/rapporter/index‐b‐n‐a.html , the latter through the Ministry's parallel Norwegian‐language site.     

Bringing Society Back into the Climate Debate

Debate over climate change focuses narrowly on the reduction of greenhouse gas emissions. A common justification for such emissions reductions is that they will lead to a reduction in the future impacts of climate on society. But research from social scientists and others who study environment–society interactions clearly indicates that the dominant factors shaping the impacts of climate on society are societal. A greater appreciation for this body of research would allow for consideration of a broader base of policy options to respond to the challenges of climate change, as well as the composition of climate research portfolios more likely to contribute useful knowledge to decision makers.     

Internal consistency of demographic assumptions in the shared socioeconomic pathways

A new set of alternative socioeconomic scenarios for climate change researches—the shared socioeconomic pathways (SSPs)—includes for the first time a more comprehensive set of demographic conditions on population, urbanization, and education as the central scenario elements, along with other aspects of society, in order to facilitate better analyses of challenges to climate change mitigation and adaptation. However, it also raises a new question about the internal consistency of assumptions on different demographic and economic trends under each SSP. This paper examines whether the interactions between the demographic and economic factors implied by the assumptions in the SSP projections are consistent with the research literature, and whether they are consistently represented in the projection results. Our analysis shows that the interactions implied by the demographic assumptions in the SSPs are generally consistent with findings from the literature, and the majority of the assumed relationships are also evident in the projected trends. It also reveals some inconsistency issues, resulting mainly from the use of inconsistent definitions of regions and limitations in our understanding of future changes in the patterns of interactions at different stages of socioeconomic development. Finally, we offer recommendations on how to improve demographic assumptions in the extended SSPs, and how to use the projections of SSP central elements in climate change research.     

R. F. Harrod on Reviving the Birth Rate

Continuing below‐replacement fertility and projected declines in population size are demographic features of many European countries and Japan. They are variously met with complacent acceptance, calls for higher rates of immigration, or—often last and least—proposals for increasing the birth rate. Fertility was also low in the 1930s, and some of the policy debate from that period resonates today. In England and Wales, fertility then had been declining for half a century. Over the decade 1931–40, it averaged 1.8 children per woman—moreover, with net emigration. Worries over this situation and its likely consequences led to the setting up in 1944 of a Royal Commission on Population, charged with considering “what measures, if any, should be taken in the national interest to influence the future trend in population.” In a memorandum submitted to the Commission in that year, the economist R. F. Harrod set out a detailed proposal to encourage childbearing through a scheme of family endowments. Part of the introductory section of Harrod's submission, arguing the case for state intervention and for material rather than ‘spiritual’ measures, is reproduced below. An evident problem in offering economic incentives for childbearing is that, to induce a given behavioral change, well‐off families would require much larger incentives than the poor. Hence child endowments that aspire to effectiveness across the income distribution have to be skewed toward the upper end. Harrod argues that this is as it should be, that policy should establish neutrality between large and small family sizes, and that this is a conceptually separate issue from poverty alleviation. ‘We should seek a re‐distribution of national income favourable to the parents of larger families and the plan should be put into effect whether or not another re‐distribution as between rich and poor is proceeding at the same time.’ He remarks on the implausibility of the government's being able to ‘talk up’ fertility— thereby generating some kind of costless ideational change, a ‘spiritual aufklärung.’ Later pans of the submission not reprinted here cover the specific details of the proposal. The proposed annual benefit per child (intended for every child after the second, with half‐rates payable for the second child) is paid for 18 years. It is substantial and increases with the child's age—at ages 13–18, for most of the income range it amounts to 20–30 percent of the father's income (or mother's, if hers is higher). Harrod also discusses further the rationale for making the endowments (and the compulsory contributions—a flat 5 percent of income—that finance them) proportional to income. To make his case Harrod draws on the dysgenic and population‐quality arguments popular at the time: worry about ‘race decline’ and ‘a general lowering of standards and of efficiency if the parents who are best equipped in experience, knowledge and culture are relatively infertile.’ In the event, the Commission recommended a flat schedule of family allowances, together with tax exemptions for dependent children calculated to provide some income‐based benefit. These were justified on population as well as equity and welfare grounds, ‘since the handicaps of parenthood have played a large part in the fall of average family size below replacement level.‘ Population quality issues—the subject of several other submissions—were sidestepped by calling for further research. By the time the Commission's report was finally published, in 1949, the baby boom was well underway: average fertility over 1946–50 was 2.4. Roy Forbes Harrod (1900–78) was one of the foremost economists of his day. His career was largely spent at Christ Church College, Oxford. A student and sometime colleague of Keynes, his best‐known early work was centered on identifying a dynamic equilibrium growth path for the economy—building on Keynes's static equilibrium analysis. As stylized (by others), this came to be called the Harrod‐Domar growth model, a formulation basic to growth theory. Harrod was editor of the Economic Journal for the period 1945–66. He was active in politics and as an economic adviser to both Labour and Conservative governments. He was knighted in 1959. The extract is reprinted from volume 5 of the Papers of the Royal Commission on Population (London: His Majesty's Stationery Office, 1950), pp. 80–85.     

Population and global warming with and without CO2 targets

The sensitivity of future global warming to variable population growth rates is reexamined as part of an ongoing debate over the extent to which climate change should be added to the list of concerns surrounding population growth. The UN 1992 low, medium and high population projections out to the year 2150 are run through an integrated climate-economics model which allows the effect of population variability to be traced through to CO₂ emissions, concentrations, warming and economic growth.We treat separately the cases of population's role in global warming, first without and then with specified atmospheric targets. Without targets, modeled CO₂ concentrations in year 2150 show great variability ranging from 600 ppm (UN low projection) to 1375 ppm (UN high projection). Such numbers suggest the potential effect of variable population growth on climate is large and that population policy options carry with them a significant, longterm, global warming mitigation component. The range of global warming achieved is not as sensitive to population because of weakened radiative absorption at high CO₂ levels. With respect to targets, with low population, stabilization at 650–750 ppm is achieved with relatively modest cuts in carbon intensity. Stabilization at 350–450 ppms requires steep cuts in emissions that are only weakly affected by the full range of variable population growth rates. Stabilization at 550 ppm is thus a transitional point between these end-member roles for population. Future work needs to address cost issues which could change this assessment of the role of population with CO₂ targets.     

Relative Cohort Size,Relative Income,and Married Women's Labor Force Participation: United States, 1968–2010

Relative cohort size—the ratio of young adults to prime‐age adults—and relative income—the income of young adults relative to their material aspirations—have experienced substantial changes over the past 40 years. Results here show that changes in relative cohort size explain about 60 percent of the declines in women's starting wage—both relative and absolute—in 1968–82, and 97 percent of its increase in 1982–2001. Relative income is hypothesized to affect a number of behavioral choices by young adults, including marriage, childbearing, and female labor force participation, as young people strive to achieve their desired standard of living. Older family income—the denominator in a relative income variable—increased by 59 percent between 1968 and 2000, and then declined by 9 percent. Its changes explain 47 percent of the increase in the labor force participation of white married women in their first 15 years out of school between 1970 and 1990, and 38 percent of the increase in hours worked in the same period. The study makes use of individual‐level measures of labor force participation and employs the lagged income of older families in a woman's year‐state‐race‐education group to instrument parental income and hence material aspirations.     

China's New Demographic Reality: Learning from the 2010 Census

China conducted its sixth modern census in 2010, recording a total of 1.34 billion people. This article presents an overview of the early census results. The data are of reasonable quality but contain some apparent defects where adjustments may be required. The census confirms that China has entered the era of demographic modernity and depicts the vast transformation of the country's rural‐urban distribution. Life expectancy has risen by 3–4 years in the decade since the last census, while fertility remains well below replacement—probably as low as 1.5 births per woman—and the sex ratio at birth is still significantly elevated. Low fertility and falling old‐age mortality are leading to continued and rapid population aging. Several coastal provinces grew by as much as 40 percent in the last decade, while a number of inland provinces have recorded population decline. China has reached an overall urban proportion of 50 percent.     

Social Security in China: Government White Paper

The largest financial problem faced by many aging societies is how to support their older, retired members. That support was once wholly a matter for individual families, with perhaps a minimal safety net offered by charitable institutions. Increasingly, in the usual course of economic development, the requisite transfers become a responsibility of the state—financed either through tax revenues or by pensions offered by (or required of) employers. The combination of lengthening life expectancy at later ages and falling fertility, however, makes those transfers ever more onerous as fewer workers are expected to support greater numbers of retirees. The situation is often likened to the approaching collapse of a Ponzi scheme. Not surprisingly, governments see an attractive solution in what is in effect a reprivatization of responsibility—not back to the family but right to the individual, through a system of individual retirement accounts (albeit with considerable state supervision). The financial trans‐fers—savings and later dissavings—then take place over each person's life cycle. Establishing a social security system—through pay‐as‐you‐go transfers, individual retirement accounts, or some combination of the two—is a major institution‐building and administrative task for a developing country, the more so in the context of rapid population aging. China is certainly a case of rapid aging, with the proportion of the population over age 60 projected to rise from 10 percent in 2000 to 20 percent by 2025 and 30 percent by 2050. The document excerpted below, a 2004 White Paper issued by the government of China, describes China's current social insurance provisions and the proposed expansion of coverage (beyond government employees and the urban formal sector) over coming years. In urban areas, it envisages pension coverage of “all eligible employees,” with an increasing emphasis on personal accounts. (Not mentioned is the situation of the large “floating population” of informal rural‐to‐urban migrants.) In rural areas, reliance on family support perforce continues: in 2003, only 2 million farmers are reported as drawing old‐age pensions. A safety‐net provision for the destitute elderly with no family provides for another 2.5 million. The document mentions various experimental schemes in rural areas. One, for medical insurance, covers 95 million residents; another offers an annual “reward” to those over 60 who have only one child (or two girls). The excerpts comprise sections I (Old‐age Insurance) and X (Social Security in Rural Areas) and the Conclusion of the White Paper, China's Social Security and Its Policy, issued by the Information Office of the State Council, Beijing, September 2004.     

Abrupt Climate Change: Inevitable Surprises

Climate change is now well recognized as a potentially significant factor in the human future, affecting ecological systems, agriculture, health, and settlement patterns. The scientific consensus, periodically assessed by the Intergovernmental Panel on Climate Change, foresees a long‐term atmospheric warming of a few degrees over a century. The accumulating knowledge of the world's climate history, however, suggests that any implied stability of trend may be illusory. The evidence comes from ice and seabed cores and tree rings, which can yield year‐by‐year information on atmospheric conditions and time‐series of mean temperatures extending back for millennia. These data show many episodes of a sudden rise or fall in temperature in particular regions, sometimes of 10°C or more in ten years, with the new mean lasting for decades or centuries. There is thus the likelihood—even the inevitability—of comparably large and abrupt changes occurring in coming years, a very different prospect from the “greenhouse warming” scenario projected by current large‐scale climate models. Moreover, the two phenomena may be connected: a continued slow temperature rise may at some point trigger an abrupt shift in climate regime through mechanisms such as the effect on ocean circulation. In 2002 a committee set up by the US National Research Council reviewed what is known about this subject in a report, Abrupt Climate Change: Inevitable Surprises (Washington, DC: National Academy Press). The Council is the operating arm of the US National Academy of Sciences; the Committee on Abrupt Climate Change comprised mostly oceanographers and climate experts and was chaired by Richard B. Alley, Professor of Geosciences, Pennsylvania State University, a glaciologist and author of The Two‐Mile Time Machine: Ice Cores, Abrupt Climate Change, and Our Future (Princeton, 2000). A recent spate of media attention to the subject has been occasioned less by the NRC report itself than by a dramatic scenario exercise derived from it, prepared under US Defense Department auspices, and by release of a disaster film with an instant‐ice‐age theme. The Pentagon study, An Abrupt Climate Change Scenario and Its Implications for United States National Security, authored by Peter Schwartz and Doug Randall, was issued in October 2003. It explores the hypothetical geopolitical consequences of a repetition in the near future of an event experienced 8,200 years ago (as recorded in an ice core from central Greenland): a sudden cooling of some 2–3° C, lasting for a century, punctuating climatic conditions broadly similar to those of the present day. In the scenario, the collapse of ocean heat‐conveying currents causes rapid cooling in the northern hemisphere and warming in the southern hemisphere. Outcomes include resource wars, large population movements, and “a significant drop in the human carrying capacity of the Earth's environment.” In February 2004 the NRC reasserted the more measured voices of its committee by issuing a four‐page summary of the 2002 report, under the same title as the full document. This “report in brief” is reproduced below.     

Alvin Hansen on Economic Progress and Declining Population Growth

The driving forces of economic growth, according to the mainstream of classical economic thinking, are threefold: technological innovations, the opening up of new territories and discovery of new resources, and increase in population. In interaction, in an entrepreneurial market economy, these forces generate growth not only in the aggregate but also per capita. Evidence of their power was seen in the long stretch of rising living standards in the West over the nineteenth century, despite the ups and downs of the business cycle. However, the economic experience of the interwar years, and in particular the Great Depression of the 1930s, suggested that the forces were largely spent and hence that future economic prospects were gravely imperiled. The Keynesian revolution in economics was a response to the evident malfunctioning of the capitalist economic system, although the policy recipes it offered (for increasing demand and investment to levels capable of generating an equilibrium consistent with full employment of productive resources, especially labor) by no means commanded unanimity. The most prominent American contributor to and spokesman for the new line of economic analysis—often called “the American Keynes”—was Alvin H. Hansen (1887–1975), who took up his professorship of political economy at Harvard in 1937, just after the appearance of Keynes's General Theory. In that post, which he held until his retirement in 1956, he was one of the most influential economists of the era as a theorist, policy adviser, and teacher. Hansen interpreted the economic problems of the 1930s not just as the manifestation of a particularly sharp cyclical downturn, but as evidence of secular stagnation caused by the closing of the economic frontier, sluggishness in technological innovation, and, not least, “a drastic decline in population growth.” This “stagnation thesis” is most succinctly set out in his presidential address to the American Economic Association, delivered in Detroit, 28 December 1938, under the title Economic Progress and Declining Population Growth. The address is re‐produced below from the March 1939 issue of the American Economic Review. (The opening paragraphs of the address, and two paragraphs, immediately preceding the closing paragraph, in which Hansen discusses changes in US national income in the 1930s, have been omitted.) Hansen's analysis of the effects of declining population growth in many ways echoes the thesis set out by Keynes in his seminal Galton Lecture delivered to the Eugenics Society in 1937 (reprinted in the Archives section of PDR 4, no. 3): a demographic slowdown decreases opportunities for profitable investments and increases levels of attempted saving, hence pushes the economy toward a low‐growth equilibrium at which resources are underutilized and unemployment is high. Hansen puts special emphasis on demographically induced shifts in the composition of output. He suggests that, beyond its direct positive effect on investment and output, population growth also has an indirect enhancing effect on these factors by facilitating technological progress–contrary to the “older Malthusian view.” In his policy proposals Hansen was more interventionist than Keynes, advocating a more intrusive government role in the economy as a possible means of escaping the vicious cycle of low demand and high unemployment. As to government action to reverse demographic trends seen as deleterious, neither Keynes nor Hansen argued for policies to increase fertility, presumably because they saw them as both inappropriate and, in comparison to remedial economic policy measures, inefficient or unfeasible. The demands of the war economy in the years following Hansen's address took care of the employment problem, and the immediate postwar decades brought the stimuli of pent‐up consumer demand, an outpouring of technological innovations, a reopening of the economic frontier produced by a more liberal trade regime, and, also, an acceleration of population growth. The result was rapid overall economic growth and increasing levels of per capita income. Keynesian demand management played some role in this economic success story: by the end of the 1960s even US President Richard Nixon pronounced himself a Keynesian. But it offered no remedy for the stagflation that eventually followed. The growth‐promoting recipes favored in the last decades of the century (especially in the most successful developing economies) were anything but Keynesian: limited government, fiscal restraint, and globalization. Yet recent and anticipated demographic trends, especially in Europe—notably fertility decline and population aging—make Hansen, once again, interesting reading. Commitments of the modern welfare state for health care, retirement pensions, and job security command wide approval, but they have boosted governments' weight in the economy and made labor markets inflexible, unemployment high, and retirement early—developments that may increasingly impose a brake on economic growth and on improvements of living standards. Reform measures to ease these burdens are, in principle, straightforward, but their immediate social costs are heavy and their rewards are delayed, hence resistance to reform is strong and growing. This is likely to stimulate the search for alternative policies that offer politically more palatable tradeoffs—some of which may turn out to have an unmistakably Hansenian flavor. As to future population trends, Hansen, despite his reference to a “drastic decline in population growth” based on a comparison of nineteenth‐ and twentieth‐century Western demographic change, envisaged a convergence to a stationary population or a tendency toward very slow decrease. Yet some economies are already locked into a demographic pattern that augurs sharper declines and more rapid population aging, enhancing the relevance of the issues posed by Hansen. In Germany, for example, in the absence of immigration, the population between ages 20 and 40 will decline from 21.6 million in 2005 to 16.3 million in 2025—a drop of 23 percent. Over the same time period, the population aged 60 and older will grow from 20.5 million to 25.8 million—an increase of 26 percent. Serious efforts to slow population decline and retard population aging by stimulating fertility would of course add another major burden to government budgets.     

Son Preference and the Persistence of Culture: Evidence from South and East Asian Immigrants to Canada

Preference for sons over daughters, evident in China's and South Asia's male sex ratios, is commonly rationalized by poverty and the need for old‐age support. In this article we study South and East Asian immigrants to Canada, a group for whom the economic imperative to select sons is largely absent. Analyzing the 2001 and 2006 censuses, 20 percent samples, we find clear evidence of extensive sex selection in favor of boys at higher parities among South and East Asian immigrants unless they are Christian or Muslim. The latter finding accords with the explicit prohibition against (female) infanticide—traditionally the main sex‐selection method—in these religions. Our findings point to a strong cultural component to both the preference for sons and the willingness to resort to induced abortion based on sex.     

Vladimir Putin on Raising Russia's Birth Rate

The total fertility rate in what is now the Russian Federation has been below replacement level during much of the last 40 years. By the late 1990s it was barely above 1.2 children per woman. There may have been some recovery since: the United Nations estimate for 2000–05 is 1.33. Other reports set the 2004 rate at 1.17. Countries elsewhere in Europe have fertility levels that are equally low or even lower, but the Russian demographic predicament is aggravated by mortality that is exceptionally high by modern standards. Thus, despite large‐scale net immigration (mostly due to return of ethnic Russians from other republics of the former Soviet Union), the population in the last decade‐and‐a‐half has been shrinking: of late by some 700,000 persons per year. The United Nations medium estimate assumes a steady recovery of the total fertility rate to reach a level of 1.85 by 2050 and a considerable improvement in survival rates during that period—notably an increase in male life expectancy at birth of more than ten years. It also assumes further modest net immigration at a steady rate, amounting to a total of somewhat over 2 million by midcentury. Under these stipulations the projected population of Russia in 2050 would be 112 million—some 31 million below its present size. By that time, 23 percent of the population would be aged 65 and older. The government's concern with the demographic situation of the country and its intent to improve it have been manifest in various official statements, notably in the annual State of the Nation Address given by the president to the Federal Assembly (or State Duma). Formerly a subordinate theme (see the Documents item in the June 2005 issue of PDR), the issue constituted the centerpiece of the 2006 Address, delivered on 10 May in the Kremlin by President Vladimir Putin. Policies regarding health and mortality were given short shrift in the speech—road safety, bootleg alcohol, and cardiovascular diseases being singled out as areas of special concern. The president's remarks on immigration are of greater interest: immigration of skilled persons is to be encouraged. They must be educated and law‐abiding and must treat the country's culture and national tradition with respect. The main focus of the address, however, was on the birth rate and policies to be introduced to raise it. (The need for an “effective demographic policy” as seen from the Kremlin was of course also voiced in the later stages of the Soviet era. See, for example, the excerpts from the addresses delivered by then Party Chairman Leonid Brezhnev and Premier Nikolai Tikhonov to the 26th Congress of the Communist Party of the Soviet Union in February 1981 that appear in the Documents item in the June 1981 issue of PDR.) In detail and specificity, and also in terms of the economic cost of the measures envisaged, Putin's speech is without parallel in addressing population policy matters by a head of state in Europe. The demo graphically relevant portion of the address is reproduced below in the English translation provided by the website of the president's office « http://www.kremlin.ru/eng ». Calling Russia's demographic situation “the most acute problem facing our country today,” Putin terms its causes as “well known,” but lists only economic factors, presumably because these, at least in principle, lend themselves to remedial measures that the Russian government, its coffers now swollen with petrodollars, should be able to provide. His starkly economic interpretation of the problem of low fertility (in Russia apparently taking the form of convergence to a single‐child pattern) may be overly optimistic. Causes of electing to have only one child may lie deeper than those Putin names: low incomes, inadequate housing, poor‐quality health care and inadequate educational opportunities for children, and even lack of food. Putin's proposed policies to attack these problems in part consist of a major upgrading of existing child care benefits: to 1,500 roubles a month for the first child and 3,000 roubles for the second. The latter amount is roughly equivalent to US$113, a significant sum given Russian income levels. Maternity leave for 18 months at 40 percent of the mother's previous wage (subject to a ceiling) and compensation for the cost of preschool childcare round out the basic package proposed. Benefits are to be parity‐dependent, highlighting the pronatalist intent of the measures. Thus the child benefit for the second child is to be twice as large as for the first, and payment for preschool childcare is to cover 20 percent of parental costs for the first, 50 percent for the second, and 70 percent for the third child. Putin mentions “young families” as recipients, but the payments are clearly directed to mothers. (Even the usually obligatory reference to western European–style paternity leave is missing.) The most innovative element of the proposed measures, however, is support for women who have a second birth. The state should provide such women (not the child, as called for in some European precedents) “with an initial maternity capital that will raise their social status and help resolve future problems.” Citing expert opinion, Putin says that such support “should total at least 250,000 roubles [about $9,300] indexed to annual inflation.” Evidently assuming, optimistically, that there will be many takers, Putin says that carrying out all these plans will require not only a lot of work but also “an immense amount of money.” The measures are to be launched starting January 2007.     

Impacts of population change on vulnerability and the capacity to adapt to climate change and variability: a typology based on lessons from “a hard country”

This article describes and analyzes the impacts of population and demographic change on the vulnerability of communities to climate change and variability. It begins with a review of existing literature on the effects of population change on anthropogenic greenhouse gas emissions, the exposure of settlements to climate risks, and on the capacity to adapt to climate change. The article explores the relationship between population change and adaptive capacity through detailed examination of empirical findings from a study of small communities in eastern Ontario, Canada currently experiencing a combination of changes in local climatic conditions and rapid demographic change caused by in-migration of urban retirees and out-migration of young, educated people. The combination of changing demographic and climatic patterns has placed increased stress on local social networks that have long been critical to climate adaptation in that region. The case study and literature review are used to create a general typology of the relationship between population change and vulnerability that may be used as a framework for future research in this field.     

Intergenerational transfers in US county-level CO2 emissions, 2007

Research has shown that increases in carbon emissions and resulting climate change are not driven by population size alone, but also associated with industrialization, urbanization, and economic development. Further, industrialization and development may, in part, be driven by changing demographic structure, and in particular the process of population aging. Fluctuations in age composition shape aggregate production and consumption. Viewed through this lens, the carbon dioxide emissions of an analytical unit (county, province, state, nation) can be considered a product of its age composition. This analysis tests several demographic theories of age-specific production and consumption on US county-level carbon dioxide emissions. Using a modified STIRPAT framework, econometric estimates identify a positive correlation between county-level labor force participation and total carbon dioxide emissions. These effects are a result of general economic activity as opposed to growth only in energy intensive industrial sectors, a relationship that is widely hypothesized but under-developed in carbon emission estimates. In addition, results show larger households are associated with lower aggregate emissions, confirming the hypothesis that areas of declining household size will experience higher future emissions. In general, this research demonstrates the importance of adding nuance to emission estimates by integrating demographic dimensions beyond population size and growth.     

Economic Growth and Child Undernutrition in sub‐Saharan Africa

Despite recent improvements in economic performance, undernutrition rates in sub‐Saharan Africa appear to have improved much less and rather inconsistently across the continent. We examine to what extent there is an empirical linkage between income growth and reductions of child undernutrition in Africa. We pool all DHS surveys for African countries, control for other correlates of undernutrition, and add country‐level GDP per capita. We find that a 10 percent increase in GDP per capita is associated with 1.5 to 1.7 percent lower odds of being stunted, 2.8 to 3.0 percent lower odds of being underweight, and 3.5 to 4.0 percent lower odds of being wasted. Other drivers of undernutrition, including relative socioeconomic status and mother's education and her nutritional status, are quantitatively more important. This suggests that further increases in GDP will have only a modest impact on undernutrition and broader interventions are required to accelerate progress.     

Income per Natural: Measuring Development for People Rather Than Places

It is easy to learn the average income of a resident of El Salvador or Albania. But there is no systematic source of information on the average income of a Salvadoran or Albanian. We estimate a new statistic: income per natural—the mean annual income of all people born in a given country, regardless of where those people now reside. Income per natural often differs substantially from income per resident, both in its mean and in its distribution. A large part of this difference is caused by movement across borders. Indeed, for people from a number of developing countries, departing their country of birth is one of the most important sources of poverty reduction and material advancement. If economic development is that which raises human well‐being, then crossing international borders is not an alternative to economic development; it is a form of economic development.     

Population,Development and Global Warming: Averting the Tragedy of the Climate Commons

Carbon emissions from fossil fuel use and other human activity are predicted to cause a significant warming of the global climate, according to a growing consensus of scientists. Global warming would have substantial negative effects on the world environment and economy. Human population and economic growth continue to drive both energy use and carbon emissions. While the developed countries are the largest source of present and past emissions, developing countries are rapidly catching up. China will probably surpass the United States as the largest carbon emitter early in the next century. The global warming treaty signed in Rio in 1992 relies entirely on voluntary emission caps for developed countries and has had little or no apparent effect on emissions. Much stronger steps must be taken to avoid or lessen potential climate change. A globally determined but nationally imposed carbon tax should be adopted to internalize the future costs of carbon emissions into the present cost of fossil fuel and other carbon sources. This would allow the maximum use of free market forces and individual choice to determine how carbon emission reductions are achieved. In addition, national emission caps for all countries should be established. International trade mechanisms can be used to support universal implementation of these measures. Where possible, global warming policy should include strong but equitable incentives for sustainable development and population stabilization, important goals in themselves regardless of the extent of future climate change.