By many accounts, climate change is already driving human migration, but fresh thinking about the consequences of increasingly stringent borders, the intervening effects of global and local policy and how best to characterize human adaptive responses is needed to properly understand whether a crisis is on the horizon.
Human migration is an important climate change adaptation strategy, but there are many gaps in our understanding of the complex, multi-faced interaction between environmental change and human mobility. Estimates for the number of environmental migrants by 2050 range from 25 million to 1 billion, so understanding when, where and how people will move (if at all), what it means to be a climate migrant and how best to govern the problem are crucial. In this Focus Collection, Nature Climate Change presents a range of Comments, News, Perspectives and primary research exploring these questions.
News & Comment
Minimizing the adverse consequences of sea-level change presents a key societal challenge. New modelling is necessary to examine the implications of global policy decisions that determine future greenhouse gas emissions and local policies around coastal risk that influence where and how we live.
Misleading claims about mass migration induced by climate change continue to surface in both academia and policy. This requires a new research agenda on ‘climate mobilities’ that moves beyond simplistic assumptions and more accurately advances knowledge of the nexus between human mobility and climate change.
Climate change is likely to increase human migration, but future climate-related migration flows will depend heavily on the adaptive capacity of people living in vulnerable regions and on the border policies of potential destination countries. Current opportunities for mobility are constrained by increasingly strict border enforcement and the securitization of international migration.
Rising sea levels threaten to displace millions of people through direct inundation and increased exposure to related hazards. This Review highlights populations at risk from sea-level-rise-related migration and discusses individual and institutional factors that influence relocation decisions.
Moving whole communities away from the coastline sounds like a remote possibility. But as sea levels rise, relocation might be an increasingly inevitable, though challenging, option.
Research into human displacement drives debate about migration and human rights.
Migration is an important means to cope with the impacts of climate-related shocks. Research shows that networks of prior migrants aid this crucial adaptation mechanism.
It is assumed that sea-level rise due to climate change will be so severe that those living near sea level will be forced to relocate. However, new research around a series of islands that have suffered subsidence due to a recent earthquake suggests that instead, island residents remain and use a range of strategies to adapt to regular flooding.
Global warming and sea-level rise will potentially impact millions of people in coastal zones. New research shows that such migration will affect all US states, including inland states which are unprepared for such an inflow of residents.
Projected sea-level rise and increased flooding threaten coastal agriculture. Gradual increases in soil salinity, but not inundation alone, are shown to correspond to increasing diversification into aquaculture and higher levels of internal migration.
Sea-level rise will impact heavily populated coastal areas, necessitating adaptation or migration. This study considers how potential migration away from affected areas will have a broader effect on the US population landscape.
Homo sapiens evolved in Africa, but the timing of our ancestors' dispersal to the rest of the world has been a source of controversy. Here Axel Timmermann and Tobias Friedrich model the dispersal in the context of the pronounced changes in climate and sea-level during the past 125,000 years. Their results suggest that dispersal across the Arabian Peninsula and the Levant was not a single event, but was concentrated in four distinct waves between 106,000 and 29,000 years ago. The findings agree with archaeological data and show that orbital-scale global climate swings played a key role in population movements, whereas millennial-scale abrupt climate changes had more limited, regional effects.
Climate change may drive migration from affected regions. This study shows that, because skilled individuals will have greater migration opportunities, climate change may lead parents to have fewer children and invest more in each individual child, with consequences for local income inequality.
Small-island communities in the Philippines prefer local measures to relocation in response to sea-level rise
It is often assumed that increased flooding due to sea-level rise will lead to mass migration. However, this study shows that residents of island communities in the Philippines prefer to implement local adaptation measures in response to frequent severe flooding rather than relocate.
Managed retreat is a potentially important climate change adaptation option. In this article the drivers and outcomes of, and barriers to, 27 recent cases of managed retreat—involving the resettlement of approximately 1.3 million people—are evaluated.
Evidence on the relationship between human migration and climatic events is limited. Now research links information from a longitudinal survey in rural Pakistan to satellite-derived measures of climate variability. Results show that heat stress consistently increases the long-term migration of men owing to impacts on income.