Leiwen Jiang | Shanghai University (original) (raw)

Papers by Leiwen Jiang

Sustainability

This study examines the migration intentions of young people in Egypt before and after the 2011 r... more This study examines the migration intentions of young people in Egypt before and after the 2011 revolution, driven by three sets of factors: (1) individual demographic and socioeconomic characteristics, (2) household characteristics, and (3) community characteristics and political and civic participation. Logistic regression models are applied to study the determinants of intentions to live, study, or work abroad among young Egyptians (defined as individuals aged 18 to 29), using data from the Survey of Young People in Egypt (SYPE) conducted in 2009 (N = 8488) and in 2014 (N = 5885). The surveys are nationally representative, covering all governorates in Egypt. The analysis indicates that respondents’ age, gender, marital status, and employment status play a significant role in shaping migration intentions. After the 2011 revolution, the effects are dependent upon economic and institutional conditions. The employment status affects the migration intention of young people in 2009; bu...

Environmental Research Letters

Spatially-explicit population projections by age are increasingly needed for understanding bilate... more Spatially-explicit population projections by age are increasingly needed for understanding bilateral human-environment interactions. Conventional demographic methods for projecting age structure experience substantial challenges at small spatial scales. In search of a potentially better performing alternative, we develop an empirically-based spatial model of population age structure and test its application in projecting U.S. population age structure over the 21st century under various socioeconomic scenarios (SSPs). The model draws on 40 years of historical data explaining changes in spatial age distribution at the county level. It demonstrates that a very good model fit is achievable even with parsimonious data input, and distinguishes itself from existing methods as a promising approach to spatial age structure modelling at the global level where data availability is often limited. Results suggest that wide variations in the spatial pattern of countylevel age structure are plausible, with the possibility of substantial aging clustered in particular parts of the country. Aging is experienced most prominently in thinly-populated counties in the Midwest and the Rocky Mountains, while cities and surrounding counties, particularly in California, as well as the southern parts of New England and the Mid-Atlantic region, maintain a younger population age structure with a lower proportion in the most vulnerable 70+ age group. The urban concentration of younger people, as well as the absolute number of vulnerable elderly people can vary strongly by SSP.

PLoS medicine, 2018

Climate change is likely to further worsen ozone pollution in already heavily polluted areas, lea... more Climate change is likely to further worsen ozone pollution in already heavily polluted areas, leading to increased ozone-related health burdens. However, little evidence exists in China, the world's largest greenhouse gas emitter and most populated country. As China is embracing an aging population with changing population size and falling age-standardized mortality rates, the potential impact of population change on ozone-related health burdens is unclear. Moreover, little is known about the seasonal variation of ozone-related health burdens under climate change. We aimed to assess near-term (mid-21st century) future annual and seasonal excess mortality from short-term exposure to ambient ozone in 104 Chinese cities under 2 climate and emission change scenarios and 6 population change scenarios. We collected historical ambient ozone observations, population change projections, and baseline mortality rates in 104 cities across China during April 27, 2013, to October 31, 2015 (20...

Vienna Yearbook of Population Research

Environmental pollution (Barking, Essex : 1987), Jan 22, 2017

A warming climate is anticipated to increase the future heat-related total mortality in urban are... more A warming climate is anticipated to increase the future heat-related total mortality in urban areas. However, little evidence has been reported for cause-specific mortality or nonurban areas. Here we assessed the impact of climate change on heat-related total and cause-specific mortality in both urban and rural counties of Jiangsu Province, China, in the next five decades. To address the potential uncertainty in projecting future heat-related mortality, we applied localized urban- and nonurban-specific exposure response functions, six population projections including a no population change scenario and five Shared Socioeconomic Pathways (SSPs), and 42 temperature projections from 21 global-scale general circulation models and two Representative Concentration Pathways (RCPs). Results showed that projected warmer temperatures in 2016-2040 and 2041-2065 will lead to higher heat-related mortality for total non-accidental, cardiovascular, respiratory, stroke, ischemic heart disease (IHD)...

Global Environmental Change, 2016

This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, la... more This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation. The pathways were developed over the last years as a joint community effort and describe plausible major global developments that together would lead in the future to different challenges for mitigation and adaptation to climate change. The SSPs are based on five narratives describing alternative socioeconomic developments, including sustainable development, regional rivalry, inequality, fossil-fueled development, and a middle-of-the-road development. The long-term demographic and economic projections of the SSPs depict a wide uncertainty range consistent with the scenario literature. A multi-model approach was used for the elaboration of the energy, land-use and the emissions trajectories of SSP-based scenarios. The baseline scenarios lead to global energy consumption of 500-1100 EJ in 2100, and feature vastly different landuse dynamics, ranging from a possible reduction in cropland area up to a massive expansion by more than 700 million hectares by 2100. The associated annual CO 2 emissions of the baseline scenarios range from about 25 GtCO 2 to more than 120 GtCO 2 per year by 2100. With respect to mitigation, we find that associated costs strongly depend on three factors: 1) the policy assumptions, 2) the socioeconomic narrative, and 3) the stringency of the target. The carbon price for reaching the target of 2.6 W/m 2 differs in our analysis thus by about a factor of three across the SSP scenarios. Moreover, many models could not reach this target from the SSPs with high mitigation challenges. While the SSPs were designed to represent different mitigation and adaptation challenges, the resulting narratives and quantifications span a wide range of different futures broadly representative of the current literature. This allows their subsequent use and development in new assessments and research projects. Critical next steps for the community scenario process will, among others, involve regional and sectorial extensions, further elaboration of the adaptation and impacts dimension, as well as employing the SSP scenarios with the new generation of earth system models as part of the 6th climate model intercomparison project (CMIP6).

World Watch, 2009

... changes over time: a growing economy, which often accom-panies urbanization, leads to increas... more ... changes over time: a growing economy, which often accom-panies urbanization, leads to increased ... Urbanization is an inevitable, ongoing, and accelerating process, and almost all future population ... and equitable eco-nomic growth to keep pace, the rapid urbanization of future ...

Atmospheric Chemistry and Physics, 2016

Wildfires are not only a threat to human property and a vital element of many ecosystems, but als... more Wildfires are not only a threat to human property and a vital element of many ecosystems, but also an important source of air pollution. In this study, we first review the available evidence for a past or possible future climate-driven increase in wildfire emissions in Europe. We then introduce an ensemble of model simulations with a coupled wildfire–dynamic-ecosystem model, which we combine with published spatial maps of both wildfire and anthropogenic emissions of several major air pollutants to arrive at air pollutant emission projections for several time slices during the 21st century. The results indicate moderate wildfire-driven emission increases until 2050, but there is a possibility of large increases until the last decades of this century at high levels of climate change. We identify southern and north-eastern Europe as potential areas where wildfires may surpass anthropogenic pollution sources during the summer months. Under a scenario of high levels of climate change (Re...

Http Dx Doi Org 10 1080 02673030600807431, Jan 22, 2007

Slums and squatters are not widespread in most Chinese cities and towns even though China has bee... more Slums and squatters are not widespread in most Chinese cities and towns even though China has been experiencing rapid urbanization. Moreover, statistics from the 2000 Census reveal that migrants do not necessarily live in poorer housing conditions than non-migrants in urban areas; some housing facilities for the floating population, who moved without changes in household registration, are even better than those of local urban residents. Using 1 per cent of the household sample of the 2000 Census dataset, this paper examines the living conditions and their determinants of the floating population in urban China.

Population Research, Sep 1, 2010

Society & Natural Resources, 2015

During the past half century, the number of individuals affected by natural disasters worldwide h... more During the past half century, the number of individuals affected by natural disasters worldwide has sharply increased (Figure 1). Within countries, migration flows have resulted in substantial redistributions-as of 2005, 763 million people were living outside their region of birth (UNDP 2013). The potential exists for redistribution to increase exposure to natural disasters if migration flows tend toward more vulnerable locations. The analyses in this Research Note are simple, but instructive. Mexican census micro data is used to estimate municipality-scale migration streams which are coupled with a disaster database (OSSO, 2013). We then contrast the total number of individuals exposed to natural disasters between 2005-2010 to the total number of individuals that would have been exposed in the case of no migration. Why Mexico? Mexico provides an important case study due to both its long history of large-scale migration and its unique susceptibility to natural disasters and the potential impacts of climate change. Within Mexico, 6.3 million migrants (~6% of the population) moved domestically during 2005-2010 (Ruggles et al. 2003). These high levels of migration are accompanied by a particular sensitivity to climate change, due to both the larger environmental impacts expected in subtropical areas (Boyd and Ibarrarán, 2009) and the socioeconomic vulnerability of many Mexicans (Eakin, 2005; Romero-Lankao et al., 2012). Hernandez et al. (2003) suggest that up to 39 percent of the Mexican territory to be under persistent drought conditions. Some climate scenarios project that areas in southern Mexico will effectively become unsuitable for rain-fed agriculture (Adamo and de Sherbinin, 2011).

Historical Methods: A Journal of Quantitative and Interdisciplinary History, 2015

Although data for the total number of international migrant flows is now available, no global dat... more Although data for the total number of international migrant flows is now available, no global dataset concerning demographic characteristics, such as the age and gender composition of migrant flows exists. This paper reports on the methods used to generate the CDM-IM dataset of age and gender specific profiles of bilateral net (not gross) migrant flows. We employ raw data from the United Nations Global Migration Database and estimate net migrant flows by age and gender between two time points around the year 2000, accounting for various demographic processes (fertility, mortality). The dataset contains information on 3,713 net migrant flows. Validation analyses against existing data sets and the historical, geopolitical context demonstrate that the CDM-IM dataset is of reasonably high quality.

Proceedings of the National Academy of Sciences, 2015

International Journal of Population Research, 2014

Is education the best contraceptive? Using the multistate human capital projection model, our ana... more Is education the best contraceptive? Using the multistate human capital projection model, our analysis shows that the projected changes in India population vary depending on investments in education and helping women reduce unwanted fertility rates, that investments in both education and helping women in each education category—but particularly less educated women—meet their wanted fertility will have the largest impacts on India’s population projections, and that the impact from investment in reducing unwanted fertility will be much more immediate and significant than only investments in education. Our analysis also reveals that an increasing education transition rate in India will not only help to achieve a population age structure that is favorable for economic growth, but also result in a larger share of skilled labor force that help to achieve higher economic growth rate. More importantly, investment in girls’ education and achieving gender equality in education will be the mos...

International Journal of Global Energy Issues, 2004

Based on an analysis of a nationally representative rural household survey and various sources of... more Based on an analysis of a nationally representative rural household survey and various sources of aggregate statistics, we explore patterns of residential energy use in rural China within the conceptual framework of the energy transition. We find that residential energy consumption varies tremendously across geographic regions due to disparities of access to different energy sources, prices, climate, income and urbanisation level. Household demographic characteristics, in particular household size, have an important impact on residential energy use. Aggregate time series data show that the transition from biomass to modern commercial sources is still at an early stage, and cross-sectional data suggest that incomes may have to rise substantially in order for absolute biomass use to fall. We also find that energy use patterns as a function of net income, rather than total expenditure, are more consistent with the energy transition model in rural China.

The Technical Notes series provides an outlet for a variety of NCAR Manuscripts that contribute i... more The Technical Notes series provides an outlet for a variety of NCAR Manuscripts that contribute in specialized ways to the body of scientific knowledge but that are not yet at a point of a formal journal, monograph or book publication. Reports in this series are issued by the NCAR scientific divisions, serviced by OpenSky and operated through the NCAR Library. Designation symbols for the series include: EDD-Engineering, Design, or Development Reports Equipment descriptions, test results, instrumentation, and operating and maintenance manuals.