Key messages
- Involuntary migration and displacement will increasingly occur due to climate change-related slow-onset impacts and the rising frequency and intensity of extreme weather events.
- Climate change and related impacts can also result in many people, particularly poor and marginalised communities, losing their capacity to adapt by moving away. However, others will choose to stay, despite facing increasing climate risks.
- Worldwide, there is a growing number of anticipatory humanitarian actions to assist climate-related mobility and minimise displacement – with early success stories
Insight explained
The IPCC’s 6th Assessment Report (IPCC AR6 WGII, 2022) stated unambiguously and with “high confidence” that human-induced climate change has impacted human mobility1 patterns through changes in migration destinations and increasing displacement risks. The growing importance of climate-related impacts has also been highlighted by all leading international authorities on human mobility (International Organization for Migration, Internal Displacement Monitoring Centre, International Committee of the Red Cross). These dynamics are expected to be amplified as climate change impacts accelerate. For example, the recent World Bank Groundswell report provides a set of projections under different scenarios and identifies “hotspots” of internal migration in six world regions. It concludes that, in the absence of effective climate and development action, flows will accelerate between now and 2050 – concentrated in the poorest and most climate-vulnerable regions, especially in sub-Saharan Africa. On their high GHG emissions scenario there are 91.9 million internal migrants more by 2050 than on the low emissions scenario (peaking at 1.4°C–2.6°C and 0.4°C–1.6°C and warming above baseline levels by 2050, respectively).2
Especially in the rural contexts in low- and middle-income countries, migration has served as an important strategy to adapt to adverse climate impacts. Climate impacts, both slow- and rapid-onset, adversely affect habitability3 and climate-dependent livelihoods, already changing the patterns of human mobility. In particular, they can accelerate various mobility responses ranging from internal rural-urban migration to temporary involuntary displacement. Overall, climate-related effects on human mobility are diverse and complex. They vary depending on the specific climatic hazards, and the socioeconomic and political factors shaping vulnerability. A crucial yet often overlooked aspect in the policy arena is that adverse climate impacts can also render socioeconomically vulnerable groups immobile, hindering their ability to adapt. This can happen, for example, as adverse climate impacts diminish peoples’ resources to engage into migration as an adaptation, which is costly. Particularly affected by involuntary immobility are the poorest regions of the world. This is illustrated by recent multi-country evidence from Cambodia, Nicaragua, Peru, Uganda, Vietnam and Bangladesh showing that low levels of education and income are generally related to lower likelihood of out-migration after experiencing sudden-onset climate events. Additionally, deciding to remain in place despite the rising climate risks is another potential outcome, as illustrated by case studies from Chilean Patagonia, as well as Fiji and Tuvalu in the Pacific Ocean.
Human mobility is driven by many factors acting in conjunction. This, together with the limitations in available data, makes it notoriously difficult to attribute individual observed mobility events to climate change. Fortunately, relationships between climate and mobility are becoming clearer thanks to improvements in data availability and research methods, and the resulting accumulated evidence related to the historical effects. But it is important to recognise that quantitative attribution of human mobility patterns to climate change remains elusive. We have a limited – but growing – understanding of the contextual, compounding and cascading climate-mobility links.
Anticipatory action
Despite remaining knowledge gaps, it is imperative to advance policy for preparedness. It is essential to shift from a reactive (ex-post response) to an anticipatory approach for humanitarian and development actions, which entail ex-ante, longer-term planning to manage climate-related mobility and immobility. Anticipatory interventions (e.g. forecast-based financing, planned relocation) have already gained prominence in the climate, development and humanitarian communities. For example, during severe winters in Mongolia, forecast-based financing mechanisms have been deployed by the International Federation of Red Cross and Red Crescent Societies, including the distribution of livestock nutrition kits and unconditional cash transfers, to reduce livestock mortality and protect vulnerable pastoralists. In drought-affected Somalia, pilot anticipatory actions by the Food and Agriculture Organization specifically target food insecurity in the light of worsening drought conditions.
Anticipatory action can help prevent or reduce involuntary displacement among vulnerable communities, as well as the loss of ability to migrate as an adaptive strategy. Ahead of extreme weather events, anticipatory actions include strengthening shelters, the early harvesting of crops and evacuation, which in turn facilitate peoples’ return in a timely manner, reducing the likelihood of prolonged displacement. In the context of slow-onset climate change impacts such as sea-level rise, far-sighted planned (voluntary and highly consultative and participatory) relocation of whole communities will increasingly gain importance as an adaptation measure, if adaptation in situ fails. It is worth highlighting the example of Fiji, where planned relocations have been carried out in the past decade and are generally considered successful, thanks to extensive consultation of and participation by the affected communities. Guidelines have been drawn for other states to also benefit from their experience.
Implications & Recommendations
For climate negotiators and decision makers at all levels – international, national and local:
- Shift from a reactive (ex-post response) to an anticipatory approach, which entails ex-ante longer-term planning and enhancing preparedness to minimise displacement as well as inability to move driven by climate and weather impacts.
Ensure ways to accommodate interests and protect the rights of diverse socioeconomic groups representing gender, age, ethnicity, class etc. when conceiving anticipatory measures. - It is important to facilitate safe and orderly migration as an adaptive strategy to climatic pressures, including circular migration. However, to ensure that migration serves as an efficient adaptation, it remains crucial to prepare receiving areas ahead of time to absorb the inflow of climate migrants. This includes preparation of labour and housing markets, as well as cultural integration.
- Planned and voluntary relocation of whole communities should only be considered if in situ adaptation strategies fail or are not feasible (Insight 1). Learning from previous cases is crucial to minimise further negative effects for the affected communities. Top-down relocations almost always increase vulnerability. Therefore, highly consultative processes with strong participation from the affected communities are absolutely essential.
- Even in the face of increasing climate risks, some communities might be reluctant to move due to their strong attachment to the palace of origin. In such circumstances, authorities should be prepared to co-develop alternative strategies with the affected communities.

References
- The term “human mobility” includes different types of movements: within or across borders, permanent, temporary or circular, voluntary or involuntary, as well as the lack of capacity or willingness to move.
- Estimate ensemble averages are 170.3 and 78.4 million internal migrants for the “pessimistic” and “climate-friendly” scenarios, respectively.
- Human habitability can be defined as “the environmental conditions that support healthy human life, productive livelihoods, and sustainable intergenerational development” (Horton, R.M., et al. 2021. Assessing human habitability and migration. Science, 372(6548), 1279–1283. doi:10.1126/science.abi8603)