Human Migration

As environmental changes and extreme weather begin to affect people's ability to produce food, generate income, or live safely in their homes, one possible adaptation response might be for individuals to move to a new place with the hopes of increasing their livelihood and security. Migration as a result of climate vulnerability and exposure to an increasingly hazardous climate is expected to be a growing challenge for individuals, communities, and governments. Our researchers are looking at a range of scenarios to understand what factors affect people's decisions to migrate in relation to climate change influences, and what the broader impact of these migration choices may be.

Migration in Response to Drought, Flooding, and Heat Waves

How do past and future climate and weather extremes, such as drought, flooding, and heat waves, affect people's decisions to migrate? Our researchers are applying and developing advanced quantitative models to better understand migration flows and predict future migration patterns under climate change. 

One project in this area investigates the effects of climate variability on South African internal migration, using an advanced network model. Another ongoing project examines population at risk and migration dynamics under the compound flooding effect of sea level rise and river flooding at the mega-deltas.

Our researchers undertake interdisciplinary research in this area, collaborating with atmospheric scientists, hydrologists, ecologists, sociologists, and political scientists, to study environmental migration from diverse perspectives and with various techniques.

Researcher: Tingyin Xiao

How International Migration Interacts with Climate Change Damages

Providing estimates of the impact of international migration in response to climate change is challenging. Migration decisions are often multi-causal and rarely due to environmental stress alone. Both push and pull factors of international migration may vary significantly with climate change; yet the direction of the overall variation in migration is unclear. Furthermore, migration’s effect on and response to climate change damages has been little studied so far.

At the moment, migration is virtually absent from Integrated Assessment Models (IAM) - a collection of tools that can help policymakers, scientists, and economists model impacts of climate change following various scenarios of future development and policies. These models integrate information about the natural world and social choices to provide insights about the potential outcome of different policies.

A robust assessment of how migration interacts with damages, or climate change impacts on society, is of utmost importance to understand the appropriate policy response. Should we open borders and help individuals migrate to their destination of choice? What if those destination areas are also exposed and vulnerable to costly climate impacts? Our researchers are analyzing those questions by including dynamic modeling of inter-regional migration in an IAM.

Their models suggest three interactions between migration and climate change. On the one hand, people might move to areas actually more exposed to climate change than where they came from, which would increase damages. On the other hand, migration might be a successful adaptation to climate change, hence decreasing damages; conversely, damages from climate change might reduce resources necessary for people to migrate.

Researcher: Hélène Benveniste

Migration as Adaptation

Not all climate-related migration occurs in response to disasters; some people may choose to move preemptively to improve their safety, wellbeing, or economic success. Our researchers are looking at links between climate change and rural-to-urban migration in the context of emerging markets, with a regional interest in Nepal and China. They are utilizing agent-based modelling and systems analysis methods to better understand how smallholder farming communities are using migration as a way to adapt to climate change, and how farmers’ social networks influence their decision-making around adaptation.

Researcher: Nic Choquette-Levy

Post-Disaster Mobility and Inequality

In the immediate aftermath of extreme weather events, such as hurricanes, people move temporarily or sometimes permanently to find shelter, secure resources to meet their needs (e.g. medical assistance, food, electricity), search for family members or friends, and assist other people. Identifying mobility patterns of people after disasters can provide fine-tuned policy interventions to identify gaps in service delivery and emergency response planning. Moreover, population movements can also have important implications for social inequality and vice versa. In the case of Hurricane Katrina in New Orleans, for example, race and income played an important role in the recovery of affected populations, particularly with respect to displacement and migration. By understanding the linkages between inequality and mobility, properly designed policies can better prepare vulnerable populations for future extremes.

Climate change and sea-level rise make it increasingly important to better understand the response of population movements to extreme climate events. This is true for the larger concerns of long-distance migration responses as well as for disaster management concerns regarding local population mobility during and in the immediate aftermath of an event.

Our researchers are utilizing big data to analyze people's mobility before, during, and after hurricanes in the United States, with the goal of identifying systemic patterns that can inform policy and planning for future hurricane response.

Researchers: Stephanie Lackner (C-PREE Postdoc 2017-19), Tingyin Xiao