Climate change and forced migration: Observations, projections and implications

This research paper examines the complex relationship between anthropogenic climate change and forced human migration. It challenges simplistic predictions of mass migration, arguing that displacement is driven by a combination of climate processes (slow-onset changes) and climate events (sudden hazards), mediated by non-climate factors such as governance, poverty, and adaptive capacity. The author outlines three speculative scenarios for future migration based on IPCC emission storylines and discusses the significant development implications for the poorest countries, which are expected to bear the greatest burden of providing for climate migrants.

• Predicting the number of forced climate migrants is highly complex and often based on 'heroic extrapolations' due to a lack of baseline data, the influence of population growth, and the unpredictability of climate evolution. While a widely cited figure suggests 200 million climate migrants by 2050, the author argues that establishing a linear, causative relationship between climate change and migration is difficult because individual decisions are influenced by subjective economic 'pull' and environmental 'push' factors.
• Climate-driven migration is categorized into two types of drivers: climate processes and climate events. Climate processes are slow-onset changes such as sea-level rise, desertification, and salinisation of agricultural land, which erode livelihoods over time. Climate events are sudden hazards, including monsoon floods, hurricanes, and glacial lake outburst floods, which force people off their land more rapidly.
• Non-climate drivers, including government policy, population growth, and community-level resilience, are as critical as meteorological factors in determining vulnerability. A natural hazard only becomes a 'natural disaster' if a community lacks the adaptive capacity to weather the event, meaning vulnerability is a function of both exposure and the ability to recover.
• The ability to migrate is not universal but is a function of mobility and resources. Those most vulnerable to climate change may lack the financial and social capital (such as funds or existing support networks) required to move, meaning the most vulnerable are not necessarily the most likely to migrate.
• The author presents three speculative scenarios for future migration based on IPCC SRES storylines: 'The Good' (B1), where serious emissions reductions and a 'Marshall Plan' for adaptation limit migration to a 5-10% increase along existing routes; 'The Bad' (A1B), where delayed efforts lead to significant internal rural-to-urban migration and emigration of skilled youth; and 'The Ugly' (A1F1), a 'business as usual' scenario where 200 million displaced people could be exceeded and large areas of South Asia, Southern China, and the Sahel become permanently uninhabitable.
• Forced migration negatively impacts development in four primary ways: by straining urban infrastructure and services, undermining economic growth through the loss of human capital (brain drain), increasing the risk of ethnic conflict over dwindling resources, and worsening health and social indicators for the migrants themselves.
• There is a significant gap in international law regarding the status of climate-displaced people. The 1951 Convention and 1967 Protocol restrict the term 'refugee' to those fleeing persecution, leaving climate migrants without a formal legal 'home' or access to the protections and services afforded to political refugees.
• National adaptation strategies in least developed countries (LDCs) frequently ignore migration. Of the fourteen National Adaptation Programmes of Action (NAPA) submitted to the UNFCCC as of April 2007, none mentioned migration or population relocation as a policy response, often viewing migration as a 'failure of adaptation' rather than a tool for it.

APA

International Institute for Sustainable Development (n.d.). Climate change and forced migration: Observations, projections and implications. https://www.iisd.org/system/files/publications/climate_forced_migration.pdf

Chicago

International Institute for Sustainable Development. Climate change and forced migration: Observations, projections and implications. n.d. https://www.iisd.org/system/files/publications/climate_forced_migration.pdf.

Wikipedia

{{cite report |author=International Institute for Sustainable Development |title=Climate change and forced migration: Observations, projections and implications |url=https://www.iisd.org/system/files/publications/climate_forced_migration.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{internationalinstituteforsustainabledevelopmentndclimate, author = {{International Institute for Sustainable Development}}, title = {{Climate change and forced migration: Observations, projections and implications}}, institution = {International Institute for Sustainable Development}, url = {https://www.iisd.org/system/files/publications/climate_forced_migration.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }