Effect of border policy on exposure and vulnerability to climate change

Hélène Benveniste, Michael Oppenheimer, and Marc Fleurbaey

Environmental Sciences, Volume 117, Issue 43 (2020)  



This paper analyzes the effect of border policies on exposure and vulnerability to climate change impacts, for migrants and origin and host communities.  

The authors quantify the effects of border policies on population distribution, income, exposure and vulnerability, CO2 emissions, and overall temperature increase. They do this by incorporating international migration and remittances into Integrated Assessment Models (IAMs) that are widely used to estimate the economic damage caused by greenhouse gas emissions. 

Main findings: 

  • Climate change has only a marginal effect on migration. Climate change increases global international migration by 0.3 to 1.1 percent in 2100, depending on border policies, development, and climate scenarios. 
  • Border policies affect net migration in all regions. In most regions, closing borders between the Global North and Global South has similar effects to closing all borders. 
  • Migration is a key source of economic welfare for less developed regions through remittances. Most destination regions are net sending remittances regions, and vice versa. More open border policies would strongly benefit Central America, the Small Island States, and Southeast Asia—increasing their gross domestic product (GDP) per capita level by up to 2.6, 2.4, and 2.1 percent—as these regions would receive more remittances from wealthier regions than they send to poorer regions 
  • Most migrants from developing regions tend to move to areas where they are less exposed to climate-related hazards than they would have been by remaining in place. This happens because migration tends to be to wealthier regions that are less exposed to climate-related hazards. Differences in exposure and vulnerability levels across regions can be substantial, up to 10 percentage points of GDP. 
  • Border policy has negligible effect on global emissions and temperature increase but does influence region-specific emissions through changed population size and remittances. Opening borders would increase emissions in most destination regions through increased population size and decrease emissions in most origin regions as income increases through remittances do not compensate population decreases. The opposite happens when closing borders. However, differences in emissions at the regional level only have a moderate effect on global emissions and almost no effect on overall temperature change. 

The authors conclude that migration and remittances can positively contribute to climate change adaptation. They show that restrictive border policies can increase exposure and vulnerability by trapping people in areas where they are more exposed and vulnerable. They also find that reducing inequality between countries would also decrease the need and benefit to use international migration as an adaptation solution. They conclude that the consequences of migration policy should play a greater part in deliberations about international climate policy.