How might human population movements across the world be affected by global environmental changes up to 2060? This report examines both global and within-country migration trends. It finds that: millions will be ‘trapped’ in vulnerable areas and unable to move; people are as likely to move towards areas of environmental risk as to move away; but also that migration can transform people’s ability to cope with environmental change.
Environmental change will affect migration through its influence on economic, social and political drivers – which themselves affect migration. However, the range and complexity of the interactions between these drivers means that it will rarely be possible to distinguish individuals for whom environmental factors are the sole driver (‘environmental migrants’). Nonetheless, there are potentially grave implications of future environmental change for migration, requiring a strategic approach to policy that acknowledges the opportunities provided by migration in certain situations.
People are as likely to migrate to places of environmental vulnerability as from these places. For example, compared to 2000, there may be between 114 and 192 million additional people living in floodplains in urban areas in Africa and Asia by 2060. Other findings include the following:
- The complex interactions of drivers can lead to different outcomes, which include migration and displacement. In turn, these types of outcomes can pose more ‘operational’ challenges or more ‘geopolitical’ challenges. There are powerful links between them. Planned and well-managed migration (which poses operational challenges) can reduce the chance of later humanitarian emergencies and displacement.
- Environmental change is equally likely to make migration less possible as more probable. This is because migration is expensive and requires forms of capital, yet populations who experience the impacts of environmental change may see a reduction in the very capital required to enable a move.
- Consequently, in the decades ahead, millions of people will be unable to move away from locations in which they are extremely vulnerable to environmental change.
- Preventing or constraining migration is not a ‘no risk’ option. Doing so will lead to increased impoverishment, displacement and irregular migration in many settings, particularly in low elevation coastal zones, drylands and mountain regions. Conversely, some degree of planned and proactive migration of individuals or groups may ultimately allow households and populations to remain in situ for longer.
- Cities in low-income countries are a particular concern, and are faced with a ‘double jeopardy’ future. Cities are likely to grow in size, partly because of rural-urban migration trends, whilst also being increasingly threatened by global environmental change. These future threats will add to existing fragilities, whilst new urban migrants are, and will continue to be, particularly vulnerable.
Planned and facilitated approaches to human migration can ease people out of situations of vulnerability. Policymakers need to plan for migration while also acting to reduce the impact of environmental change on communities. They need to recognise the transformational opportunities of migration and that:
- Migration issues must be considered in the development of funding mechanisms for adaptation to environmental change.
- Urgent action is required to build urban infrastructure that is sustainable, flexible and inclusive. The twin challenges of population growth and environmental change will pose an increasing threat to urban areas in the future, but cities in many countries are already failing their citizens.
- Trying to prevent rural-urban migration could lead to graver outcomes for those who are trapped in vulnerable rural areas.
- The cost of inaction is likely to be higher than the costs of measures discussed in this report, especially if they reduce the likelihood of problematic displacement. Giving urgent policy attention to migration in the context of environmental change now will prevent a much worse and more costly situation in the future.