Future air pollution related health burdens associated with RCP emission changes in the UK

Three Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathways (RCPs) are used to simulate future ozone (O₃), nitrogen dioxide (NO₂), and fine particulate matter (PM_2.5) in the United Kingdom (UK) for the 2050s relative to the 2000s with an air quality model (AQUM) at a 12 km horizontal resolution. The present-day and future attributable fractions (AF) of mortality associated with long-term exposure to annual mean O₃, NO₂ and PM_2.5 have accordingly been estimated for the first time for regions across England, Scotland and Wales. Across the three RCPs (RCP2.6, RCP6.0 and RCP8.5), simulated annual mean of the daily maximum 8-h mean (MDA8) O₃ concentrations increase compared to present-day, likely due to decreases in NO_x (nitrogen oxides) emissions, leading to less titration of O₃ by NO. Annual mean NO₂ and PM_2.5 concentrations decrease under all RCPs for the 2050s, mostly driven by decreases in NO_x and sulphur dioxide (SO₂) emissions, respectively. The AF of mortality associated with long-term exposure to annual mean MDA8 O₃ is estimated to increase in the future across all the regions and for all RCPs. Reductions in NO₂ and PM_2.5 concentrations lead to reductions in the AF estimated for future periods under all RCPs, for both pollutants. Total mortality burdens are also highly sensitive to future population projections. Accounting for population projections exacerbates differences in total UK-wide MDA8 O₃-health burdens between present-day and future by up to a factor of ~3 but diminishes differences in NO₂-health burdens. For PM_2.5, accounting for future population projections results in additional UK-wide deaths brought forward compared to present-day under RCP2.6 and RCP6.0, even though the simulated PM_2.5 concentrations for the 2050s are estimated to decrease. Thus, these results highlight the sensitivity of future health burdens in the UK to future trends in atmospheric emissions over the UK as well as future population projections.

Will the COVID-19 pandemic affect population ageing in Australia?

The COVID-19 pandemic has caused extensive disruption to economies and societies across the world. In terms of demographic processes, mortality has risen in many countries, international migration and mobility has been widely curtailed, and rising unemployment and job insecurity is expected to lower fertility rates in the near future. This paper attempts to examine the possible effects of COVID-19 on Australia’s demography over the next two decades, focusing in particular on population ageing. Several population projections were prepared for the period 2019–41. We formulated three scenarios in which the pandemic has a short-lived impact of 2–3 years, a moderate impact lasting about 5 years, or a severe impact lasting up to a decade. We also created two hypothetical scenarios, one of which illustrates Australia’s demographic future in the absence of a pandemic for comparative purposes, and another which demonstrates the demographic consequences if Australia had experienced excess mortality equivalent to that recorded in the first half of 2020 in England & Wales. Our projections show that the pandemic will probably have little impact on numerical population ageing but a moderate effect on structural ageing. Had Australia experienced the high mortality observed in England & Wales there would have been 19,400 excess deaths. We caution that considerable uncertainty surrounds the future trajectory of COVID-19 and therefore the demographic responses to it. The pandemic will need to be monitored closely and projection scenarios updated accordingly.

Use of Counterfactual Population Projections for Assessing the Demographic Determinants of Population Ageing

Counterfactual population projections have been used to estimate the contributions of fertility and mortality to population ageing, a method recently designated as the gold standard for this purpose. We analyse projections with base years between 1850 and 1950 for 11 European countries with long-run demographic data series to estimate the robustness of this approach. We link this approach with stable population theory to derive quantitative indicators of the role of fertility and mortality; consider ways of incorporating net migration; and examine the effect of using alternative indicators of population ageing. A number of substantive and technical weaknesses in the counterfactual projection approach are identified: (1) the conclusions are very sensitive to the choice of base year. Specifically, the level of base year fertility has a major influence on whether fertility or mortality is considered the main driver of population ageing. (2) The method is not transitive: results for two adjacent intervals are unrelated to results for the combined period. Therefore, overall results cannot be usefully allocated between different sub-intervals. (3) Different ageing indices tend to produce similar qualitative conclusions, but quantitative results may differ markedly. (4) Comparisons of alternative models should be with a fixed fertility and mortality projection model rather than with the baseline values as usually done. (5) The standard counterfactual projections approach concatenates the effects of initial age structure and subsequent fertility and mortality rates: methods to separate these components are derived.

A New Measure of Fertility Replacement Level in the Presence of Positive Net Immigration

In most more developed countries, the total fertility rate (TFR) is below 2.1 and net immigration is positive. This paper proposes and calculates for 22 populations for 2011-15 a 'Current Migration Replacement TFR' which in combination with the mortality and absolute net migration for that period generates a stationary population equal in size to the mid-period population. The results show the Current Migration Replacement TFR ranges widely from 0.60 for Singapore to 2.05 for Slovakia. That the Current Migration Replacement TFR is below the 2011-15 TFR in 14 of the 22 countries shows that, when considered in combination with current migration and mortality, in most of the countries the current 'below 2.1' TFR is coherent with population increase, not population decline, over the long run. For New Zealand, Australia, Norway, Sweden and the UK continued current fertility in combination with constant mortality and constant absolute net migration is coherent with more than doubling of the current population size. The value of this measure for illustrating the interconnected population size implications of sub-replacement fertility and immigration, for sub-categorisation of 'post-transitional' populations by population growth prospects, and for guiding population policy is discussed.

Projections of Older European Migrant Populations in Australia, 2016-56

Many of the European migrant populations which settled in Australia in the three decades after World War Two are now much older, and their aged care and health care needs are changing. While there is a considerable literature on individual aspects of ageing in many migrant groups (particularly as it pertains to culturally appropriate aged care), little research attention has been given to population aspects of ageing and its implications. The aim of this paper is to address this lacuna by presenting projections of Australia's Europe-born older migrant population from 2016 to 2056. The population projections were created by a cohort-component model modified to accommodate multiple birthplace populations. Findings show the older Europe-born population is projected to experience a slight increase over the next few years, reach a peak of just under one million in the early 2030s, and then undergo a gradual decline thereafter. The Europe-born share of Australia's 65+ population will fall, from 25.5% in 2016 to 10% by 2056. Populations born in Western and Southern Europe are likely to decline throughout the projection horizon while, the Northern Europe-born and Ireland-born older populations are projected to grow continually. The populations born in the UK and South Eastern Europe initially grow before decline sets in. To a large extent the future population size of these older migrant groups will be the result of cohort flow. We discuss the implications of the coming demographic changes for government policy and culturally appropriate service provision.

Past and projected growth of Australia's older migrant populations

In recent years, Australia’s older population (aged 65 and over) has been growing rapidly, accompanied by a shift in its country of birth composition. Although a great deal of research has been undertaken on past and current aspects of Australia’s migrant groups, little attention has been paid to future demographic trends in older populations. The aim of this paper is to examine recent and possible future demographic trends of Australia’s migrant populations at the older ages. We present population estimates by country and broad global region of birth from 1996 to 2016, and then new birthplace-specific population projections for the 2016 to 2056 period. Our findings show that substantial growth of the 65+ population will occur in the coming decades, and that the overseas-born will shift from a Europe-born dominance to an Asia-born dominance. Cohort flow (the effect of varying sizes of cohorts moving into the 65+ age group over time) will be the main driver of growth for most older birthplace populations. The shifting demography of Australia’s older population signals many policy, planning, service delivery and funding challenges for government and private sector providers. We discuss those related to aged care, health care, language services, the aged care workforce, regulatory frameworks and future research needs in demography and gerontology.

Trends in differences between births and surviving infants reported for immunization program planning and external data sources in Eastern and Southern Africa 2000-2013

To inform our WHO team's support for immunization programs in Member States in Eastern and Southern Africa, we compared annual trends from 2000 to 2013 in target populations reported by Member States through the WHO-UNICEF joint reporting form with United Nations (UN) population projections and modeled infant mortality estimates from the UN Inter-agency Group for Child Mortality Estimation. Our findings indicated a tendency of underestimating births and surviving infants used by Member States as denominators for administrative immunization coverage rates, resulting in or contributing to overestimation of coverage. The difference with UN estimates appeared to be more pronounced for surviving infants than births. Measures of central tendency for individual country differences indicated that those differences decreased over time. Comparing trends of births and surviving infants with external sources can help monitoring progress in efforts to provide accurate and reliable target population estimates and sampling frames.