Hammered By The Climate, These Islands Are Losing the Most Residents

Climate migration is notoriously hard to model. While there is consensus that sudden and slow-onset climate hazards will lead to significant spatial redistribution of populations around the world, the details on how climate will impact worldwide mobility is highly uncertain.

Data from Meta, Harvard University, and the University of Hong Kong, however, provides one the clearest pictures yet on global migration patterns, mapping international population flows based on the locations of billions of Facebook users.

Broken down by country-to-country flow each month, the data shows how shocks like war and climate disasters fuel outbound migration around the world. The data also shows a correlation between net population loss and climate risk, with dozens of small island nations – where rising seas and shrinking coastlines could make life largely unlivable within 50 years – ceding the most residents to other, safer countries. A closer look at the data reveals the small islands the most residents are leaving.

To determine the island nations losing people to climate disaster, Climate Crisis 247 reviewed data on international migration flows from Meta. Countries were ranked based on net population change due to migration from January 2019 to December 2022. Supplemental data on climate vulnerability is from the University of Notre Dame Global Adaptation Initiative.

10. Papua New Guinea

• Net migration, 2019 to 2022: -9,823 people
• Climate vulnerability index: 0.55 (27th of 187 countries)
• Top destination countries: N/A

9. Guinea-Bissau

• Net migration, 2019 to 2022: -11,988 people
• Climate vulnerability index: 0.62 (5th of 187 countries)
• Top destination countries: Portugal, Senegal, Guinea

8. Suriname

• Net migration, 2019 to 2022: -13,913 people
• Climate vulnerability index: 0.42 (92nd of 187 countries)
• Top destination countries: N/A

7. Mauritius

• Net migration, 2019 to 2022: -15,286 people
• Climate vulnerability index: 0.41 (103rd of 187 countries)
• Top destination countries: Bangladesh, India, France

6. Sao Tome and Principe

• Net migration, 2019 to 2022: -15,924 people
• Climate vulnerability index: 0.54 (31st of 187 countries)
• Top destination countries: N/A

5. Fiji

• Net migration, 2019 to 2022: -24,856 people
• Climate vulnerability index: 0.46 (72nd of 187 countries)
• Top destination countries: Australia, New Zealand, United States

4. Cabo Verde

• Net migration, 2019 to 2022: -36,421 people
• Climate vulnerability index: 0.43 (90th of 187 countries)
• Top destination countries: Portugal, United States, France

3. Dominican Republic

• Net migration, 2019 to 2022: -77,724 people
• Climate vulnerability index: 0.43 (89th of 187 countries)
• Top destination countries: United States, Haiti, Spain

2. Jamaica

• Net migration, 2019 to 2022: -98,363 people
• Climate vulnerability index: 0.42 (96th of 187 countries)
• Top destination countries: United States, Canada, United Kingdom

1. Haiti

• Net migration, 2019 to 2022: -214,494 people
• Climate vulnerability index: 0.51 (44th of 187 countries)
• Top destination countries: Dominican Republic, United States, Brazil