# Populations on the Move ## expand\_more The current state of the world’s population is one of unprecedented diversity and change, reflected in new patterns of fertility, mortality, and migration. As demographic forces transform the size, structure and spatial distribution of populations, equally dramatic changes are occurring epidemiologically. In the most developed countries, rising chronic diseases accompany low fertility, shrinking working-age populations, and population aging. In less developed countries rising chronic diseases are superimposed on an unfinished agenda of infectious disease, maternal-child mortality, and undernutrition. In some of the world’s most vulnerable settings, continued high fertility rates are coupled with political instability, food insecurity, and displaced populations. Even in countries with declining fertility, population growth will continue for decades with youth populations expanding in the context of rapid urbanization and strained public services. While the changing age structure of a population can create a window of opportunity for economic growth, reaping this ‘demographic dividend’ is time-sensitive and dependent on the design and implementation of smart policies. ## Subthemes ### Displaced & Vulnerable ![Pen and ink sketch of people in the city.](/sites/g/files/omnuum10866/files/styles/hwp_16_9__480x270/public/2025-07/SS_407786158.jpg?h=c3fa9e01&itok=9rP8vCsL) ### Urbanization & Clients ![Pen and ink sketch of people in the city.](/sites/g/files/omnuum10866/files/styles/hwp_16_9__480x270/public/2025-07/SS_354925952.jpg?h=e84e7ba1&itok=fmpeRL5O) ### Migration & Gender ![Pen and ink sketch of people in the city.](/sites/g/files/omnuum10866/files/styles/hwp_16_9__480x270/public/2025-07/SS_350507696.jpg?h=0ca86262&itok=Hb0xTqIF) ### DISPLACED & VULNERABLE expand\_more Changing place can happen by force or by choice. However, the distinctions between refugees and migrants and voluntary and involuntary movements are becoming increasingly blurred. The reasons for displacement today are far more complex than those envisioned at the writing of the 1951 Convention on Refugees. In addition to displacement secondary to armed conflict and political upheaval, growing numbers are displaced because of natural or environmental disasters, extreme weather events, food insecurity, and development policies and projects. Of particular concern is the growing frequency with which situations of protracted displacement are emerging. It has never been more important that we consider the underlying structural drivers (environmental, social, political, and economic) as well as the proximate precipitating triggers, while prioritizing multi-stakeholder and multi-sectoral cooperation. Below are examples of resources relevant to the overarching themes. Previously highlighted resources and additional resources can be found in [our digital Repository](/). #### Resources: [Global Humanitarian Overview 2026](https://repository.gheli.harvard.edu/repository/12842) This report from the United Nations Office for the Coordination of Humanitarian Affairs (UNOCHA) assesses humanitarian needs worldwide and how to best respond to them. The report provides an overview of global trends, analyzes the drivers of humanitarian need, and discusses response plans and resources needed to effectively support communities and deliver better humanitarian assistance. This year’s report summarizes trends in crises and needs in 2025, finding that conflict and natural disasters—the main drivers of death, displacement, and hunger worldwide—have been increasingly intensifying in recent years, leading to an estimated 239 million people worldwide in need of humanitarian assistance at the beginning of 2026. [Unsafe and Unstable Housing for Refugees and Asylum Seekers Is a Threat to Intergenerational Health](https://repository.gheli.harvard.edu/repository/14305) This article, published by the British Medical Journal, examines the impact of unsafe and unstable housing on the health of refugees and asylum seekers across generations. Through a biosocial lens, the authors present evidence on the impact of unstable, unsafe, and informal housing, as well as segregation and isolation on the physical and psychological health of refugees and asylum seekers. With a special focus on women and children, the article discusses the exhaustion, isolation, and difficulties accessing health and social services that can occur as a result of unstable housing. The article brings forward migrant-sensitive recommendations on how to properly plan housing and resettlement initiatives to promote positive intergenerational health. [Expert Group on Refugee, IDP and Statelessness Statistics (EGRISS)](https://repository.gheli.harvard.edu/repository/14236) Established in 2016 by the United Nations Statistical Commission, the Expert Group on Refugee, IDP and Statelessness Statistics (EGRISS) was mandated to develop international recommendations, standards, and guidance for improved statistics on forced displacement and statelessness. EGRISS is comprised of members from 58 national statistics authorities from regions affected by forced displacement and statelessness, as well as regional and international organizations. It aims to support countries and global organizations in enhancing the collection and production of official statistics on forcibly displaced populations. ### URBANIZATION & CITIES expand\_more More than half of the world’s population now lives in urban areas. While urbanization can bring advances in social, political, and economic prospects, its pace often outstrips the development of basic public health services and infrastructure, compounding health threats that already affect the poor. For the one in three urban dwellers who reside in slums, chronic insecurities of water, food, and energy are coupled with disproportionate vulnerabilities to the consequences of climate and environmental change. Given that between now and 2050, most population growth will be in the urban cities of Africa and Asia, there is a critical window in which to re-imagine how urban development can meet the contextual challenges of the 21st century. Below are examples of resources relevant to the overarching themes. Previously highlighted resources and additional resources can be found in [our digital Repository](https://repository.gheli.harvard.edu/repository). #### Resources: [2025 Food Insecurity in Asia and the Pacific](https://repository.gheli.harvard.edu/repository/10933) This report from the Food and Agriculture Organization of the United Nations (FAO) provides a regional overview of food security and nutrition in Asia and the Pacific. This report provides the latest data on undernourishment, food insecurity, and malnutrition in the region and measures progress toward meeting the Sustainable Development Goal (SDG) 2 targets for ending hunger globally. This year’s report finds that 285.3 million people were undernourished in the region, accounting for 40 percent of people facing hunger globally. The report also provides data on the cost and affordability of a healthy diet and additionally outlines actions and priorities to accelerate transformation of agrifood systems in Asia and the Pacific. [The 2024 Annual Homeless Assessment Report (AHAR) to Congress](https://repository.gheli.harvard.edu/repository/13371) This publication by the U.S. Department of Housing and Urban Development is the Annual Homeless Assessment Report (AHAR) presented to Congress. It provides the national, state, and continuums of care-level point-in-time (PIT) count and housing inventory count (HIC) estimates of homelessness. The data for the report was based on the PIT and HIC conducted in January 2024. The report is divided into seven major sections, providing estimates on overall homelessness in the U.S., along with estimates for homelessness across several populations: individuals, families with children, unaccompanied youth, and veterans. The report provides key findings on the status of homelessness in the United States and offers recommendations to make a coordinated effort to end homelessness. [Global Burden and Trends of Transport Injuries From 1990 to 2019](https://repository.gheli.harvard.edu/repository/14490) This article, published in BMJ Injury Prevention, analyzes the global burden and trends of transportation injuries from the Global Burden of Disease (GBD) Study 2021. Transport injuries are an important cause of global disability-adjusted life-years (DALY’s) and mortality. While some high-income countries have seen reductions in fatalities due to improved safety measures, global progress has remained uneven, with increasing incidence, especially amongst people above the age of 14 years within low and middle-income countries. This article underscores the need for evidence-based road safety intervention, targeted prevention strategies, and international collaboration to reduce the burden of transport-related injuries. ### MIGRATION & GENDER expand\_more The social, economic, and environmental consequences of climate change are becoming clear, ranging from extreme weather events and droughts to losses of arable land and natural resources. Among those most affected are women and girls. Underlying social inequities and vulnerabilities compound the disproportionate burden they bear of securing shelter, food, water, and fuel. While women are more likely to suffer from both immediate health traumas and the long-term consequences of environmental change, they may also be in a better position to affect progress. Women are often the household decision-makers for health, education, and food purchases, and they can make informed choices that improve their own lot and that of their families. Embracing women’s equal and meaningful participation—as actors, leaders, and decision-makers—beyond the household builds on the momentum for gender-responsive policy actions and investments toward sustainable development. Below are examples of resources relevant to the overarching themes. Previously highlighted resources and additional resources can be found in [our digital Repository](https://repository.gheli.harvard.edu/repository). #### Resources: [How State Policies Shape Access to Abortion Coverage: Data Interactive](https://repository.gheli.harvard.edu/repository/11264) This data interactive, developed by KFF, shows the increase in states with laws restricting abortion coverage when using Medicaid and private insurance from 2010 to the present. The most recent map, accurate as of January 2025, shows that 30 states and the District of Columbia have Medicaid coverage limitations, 10 states have private insurance limitations, 25 states have state marketplace coverage limitations, and 8 states have no coverage limitations. [Human Development Data (1990-2025)](https://repository.gheli.harvard.edu/repository/11249) This data portal from the United Nations Development Programme (UNDP) shares global, regional, and country-level human development data from 1990 to 2025 across multiple dimensions, including health, education, gender, and environmental sustainability. Users can explore the data by country or dimension and narrow it down by specific indicators. All of the data is available for download. [Progress on the Sustainable Development Goals: The Gender Snapshot 2025](https://repository.gheli.harvard.edu/repository/13076) This data publication from the United Nations Entity for Gender Equality and the Empowerment of Women (UN-Women) presents the latest data on gender equality across each of the 17 Sustainable Development Goals (SDGs). The report finds that the world is still off track to attain gender equality by 2030, providing a snapshot of data for women and girls worldwide across indicators of poverty, education, violence, water and sanitation, discrimination, labor, and more. The authors break down the challenges associated with each SDG in the context of gender equality and outline six priority actions to accelerate progress for women and girls worldwide. ### Internal Displacement and Starvation in Syria Regional Profile On Monday, January 11, 2016, the besieged Syrian city of Madaya received its first shipment of foreign aid since October. [The sight of food trucks brought starving residents to tears](https://www.cnn.com/2016/01/12/middleeast/syria-madaya-starvation/index.html), a U.N. source told CNN. The situation in Madaya is dire: because the regime has choked off the rebel-held city, prices of basic food items have soared. In the capital, Damascus, flour costs 79 cents a kilogram; in Madaya, the price has soared to $120 a kilo. Moreover, landmines have made smuggling food into the city incredibly dangerous. Dr. Khaled Mohammed, who works at a field hospital in the city, said he gets about 250 cases of starvation a day. He said the hospital has seen at least 55 deaths from starvation. The situation of internally displaced civilians in Syria is representative of the growing numbers of people caught in protracted and chronic patterns of displacement and underscores the limits of humanitarian action. [Learn more about the need for concerted efforts by political and operational actors to address the underlying drivers of displacement](http://www.internal-displacement.org/publications/understanding-the-root-causes-of-displacement-towards-a-comprehensive-approach-to). ### Mass Gatherings and Health Population Snapshot Sports fans, religious pilgrims, and displaced persons all share experiences of a “mass gathering.” The World Cup, the Hajj, and life in refugee camps are all occasions where a population with shared interests crowds into a small space to share experiences and resources. Health risks at mass gatherings include infectious disease transmission, fire, stampedes, and risks to safe water, food, sanitation, and health care access. Mass gathering experiences vary, however, in mood, governance, and profit. Improving global health calls for innovations that build hope into humanitarian aid responses, mobilize local resources in strengthening disaster-related governance, and foster win-win exchanges that strengthen health, human dignity, and entrepreneurial spirit in such populations. [Learn more by reading the series entitled “Mass Gatherings Health”](http://www.thelancet.com/series/mass-gatherings-medicine) which describes the study of a range of health issues that can arise during mass gatherings. ### Designing Urban Health Sector Perspective Architects working in education and the business sector can play an important role in shaping spaces that foster health. As some features can promote resilience and others vulnerability, a community’s spatial design can have a significant impact on the social determinants of climate-related health outcomes. For instance, researchers are investigating how planning and design in cities may create conditions conducive to the multiple dimensions of health and equity in urban neighborhoods. By working with communities before disaster strikes, urban planners may help establish parks, safe walking routes, and landscape details to set the stage for connectivity within neighborhoods. Environment-friendly and adaptable spaces may also help mitigate hazards and promote healthy recovery from risks caused by crises such as flood, tornado, civil strife, earthquake, and severe winter storms. [Learn more about Environment, Climate, and Health](https://www.gsd.harvard.edu/urban-planning-design/programs/master-in-urban-planning/areas-of-concentration/), a concentration area within the Master in Urban Planning at the Harvard Graduate School of Design. ### Teaching about Health and Migration Featured How might educators—especially those in the humanities who are not health specialists—use a multidisciplinary approach to teach about migration in ways that might help strengthen global health? How might they prepare their students—whether young adults, high school, college, or graduate students—to better understand why these transitions and health risks matter in today’s world? This annotated bibliography offers a rough guide to key themes in these issues that cross over into topics commonly discussed in many high school and college classroom settings. Finding creative ways to help students think about the world’s health as it relates to migration can help nurture responsible global citizens who are prepared to live thoughtfully amidst the population shifts of the 21st century. [Learn more with additional resources](https://repository.gheli.harvard.edu/repository/10595/).