Environmental changes, including the consequences of climate change, have important effects on the health of migrants and mobile populations. Internal and international population movements often take place from environmentally fragile areas, and might result in people moving into places that are also at environmental risk, such as underserved informal settlements in urban areas, or isolated rural locations. This poses major challenges to public health systems and infrastructure. Though environmental migrants face many challenges, paramount among them is lack of access to health-care services that might be only available in limited form, as recognized in the World Health Assembly (WHA) resolution 70.15 on Promoting the health of refugees and migrants. Migrants already experience significant barriers to accessing essential health and social services, and environmental events and processes that may affect them can further exacerbate these obstacles.

Disasters, displacement and health

Following disasters, displaced persons are often subject to increased health vulnerabilities related to unsafe water, inadequate sanitation and hygiene, or malnutrition. These vulnerabilities are exacerbated by limited access to health care, which is likely to be negatively affected by the disaster and by related weakening of health systems and infrastructure. Maternal and neonatal health often severely deteriorates in displacement scenarios. As discussed in the set of chapters Mobility dimensions of crises, displaced persons are also at increased risk of mental health and behavioural disorders such as post-traumatic stress disorder, depression, anxiety, loneliness, self-harm and suicide due to exposure to intense events, experiencing physical losses, and going through disruptions in social and community networks.

Health challenges for migrants who are displaced by disasters are exacerbated in the context of health crises. For those who have fled from disasters and are now living in camps, which are often crowded, there are few (or no) health measures to handle and prevent the further spread of communicable diseases. For instance, it is difficult or impossible in such circumstances to maintain sufficient physical distance or isolate when necessary. Access to hygiene items as well as to health care may become more difficult due to disruption in provision. This results in interrupted treatment to health issues possibly developed along the journey. For those arriving in camps, or returning to home communities, these difficulties are compounded by possible violent reactions from receiving communities out of fear of contagion. This impacts the chance to find durable solutions. Measures to address these issues involve (IOM, n.d.):

  • Including migrants in preparedness and response plans;
  • Addressing living conditions in camps and ensuring procedures for evacuation in the context of disasters;
  • Observing necessary measures to prevent contagion of communicable diseases.
To Go Further
Environmental change, migration and health

Environmental change is expected to drive both the frequency and the distribution of health hazards and environmental migration (see chapter Migration, environment and climate change). For example, environmental conditions – such as high temperatures, high rainfalls and humidity coupled with pools of still sun-drenched water – will be affected by climate change, favouring the propagation of vector-borne diseases like malaria and dengue. In conjunction with potential barriers to access to health-care services and disruptions to vaccination programmes, these environmental conditions can cause outbreaks of infectious disease to spread.

Variable rainfall also plays an important role in agricultural production, often impacting yields and in some cases contributing to the increased prevalence of food insecurity and malnutrition. These dynamics, and the resulting impacts on people’s health, can become part of people’s mobility decisions, contributing to people’s migration out of areas at increased risk. At the same time, they can also affect the areas to which migrants are moving.

Especially in overcrowded urban areas, where many environmental migrants travel to, already weak health infrastructure and systems will not be able to cope with this population influx without global multisectoral assistance. Moreover, the health impacts of environmental change can also be felt through damage to available health infrastructures, as a result of the increased frequency and intensity of different natural hazards. Environmental change can therefore lead to disrupted continuity of care and insufficient access to health care.

According to the World Health Organization (WHO), climate change is expected to cause approximately 250,000 additional deaths per year between 2030 and 2050 (WHO, 2018). Much of this environment-caused mortality will affect vulnerable groups like migrants, mobile and other hard-to-reach populations who are unable to access prevention, health care and other services due to economic, geographical, social or legal barriers. Although global warming may bring some localized benefits, such as fewer winter deaths in temperate climates and increased food production in certain areas, the overall health effects of a changing climate are likely to be overwhelmingly negative (WHO, 2021).

To Go Further

Recent frameworks such as the Paris Agreement and the Sendai Framework for Disaster Risk Reduction  are examples in which environmental change and disasters, migration and health have been clearly linked. However, stronger inclusion of the health of migrants in environmental policies is fundamental to building resilience in communities and health systems bearing the burdens of climate change (further details in the policy approaches box, below). The Intergovernmental Panel on Climate Change (IPCC) has also noted that human mobility can play an important role in adaptation measures to avoid direct and indirect health impacts resulting from the effects of climate change on livelihoods and food chains.

Including health and migration health considerations in environmental policies will build health resilience in communities facing the adverse impacts of environmental change, including climate change. Some policy frameworks and documents by international organization have started to move in this direction. For example, the draft WHO global strategy on health, environment and climate change recognizes and further solidifies the connection between climate change and health. It also outlines both the current global challenges regarding these themes and the potential avenues to strengthen health systems and minimize the consequences of environmental change and related hazards. Upon request of its Member States, WHO also released an Operational framework for building climate-resilient health systems to mitigate poor health outcomes as a result of various climate change impacts. Resilient health systems and infrastructure, coupled with migrant-inclusive policies, would provide a protective and health-upholding environment in the face of climate change and increasing migration flows.

Policy Approaches
Strengthening national health systems to address impacts related to climate change
  • Include migrants, mobile and other hard-to-reach populations in strategies, policies and programmes to address the health impacts of climate change and environmental degradation on vulnerable migrants.
  • Invest in making the health systems culturally competent and inclusive of migrants (further details in Chapter Health and migration).
  • Strengthen health surveillance systems in what concerns climate-change-related risk factors and determinants, including by monitoring population flows and mapping people’s mobility.
  • Further adapt and strengthen health infrastructure to be able to resist excess damage due to climate-related natural hazards, especially in areas where established migration flows are prevalent or expected to increase.
  • Implement cost-effective population-wide disaster risk reduction and climate change adaptation, as well as disaster preparedness interventions, ensuring coverage of migrants through promotion of health literacy, awareness and improved access to health promoting environments.
  • Foster stronger partnerships between health and non-health sectors, public and private sectors, and governmental and civil society groups to overcome barriers to effective health and climate change actions.
  • As per the Sendai Framework, include migrants, displaced persons and human mobility considerations in disaster risk reduction policies and programmes to help build health systems resilience and reduce adverse health outcomes that can lead to, and result in, disasters.