By Matt Burdett, 28 February 2018
On this page, we look at the impacts of climate change on people and places, including migration.
Migration due to climate change can be short term or long term. Short term migration occurs when people are displaced from their homes for a period of time, for example due to a tropical cyclone. Long term migration occurs when people are forced to move permanently, such as due to sea levels rising.
The situation now
Currently, climate events are a factor in several displacements of people worldwide, such as tropical cyclones (also known as typhoons and hurricanes) which force people to leave their homes. However, many of the world’s hazardous events causing migration are not climatic in nature, such as earthquakes and civil war. The map below shows some selected ongoing situations from 2015-15.
- Map showing medium to long term migration and its causes in 2014-15. Source: UNFCCC, 2016.
However, there are still many climatic events that cause displacement of people. The graphic below shows that all of the top ten largest displacement events (i.e. events which forced people to move from their homes) have been related to climate in some way, and that eight of the ten occurred in Asia. This is perhaps not surprising bearing in mind that the population density of this region is very high, but it still poses challenges for the future especially as they are almost all in middle or low income countries.
- The world’s ten largest displacements in 2016. Source: ODI/UNDP, 2017.
The impact of climate change in the future is likely to result in more climate-related displacement. Coastal flooding due to sea level rise, river flooding due to rainfall, and reduced agricultural yields due to desertification are among the biggest causes of future migration. The graph below shows that weather related displacements are already greater than geophysical (earthquakes, volcanoes and slope failure), but and this is likely to continue in the future.
- Weather related displacement compared to geophysical (landslides, earthquakes and volcanoes) displacement. Source: UNFCCC, 2016.
Migration: where will it happen?
As we have seen above, eight of the ten largest displacements in 2016 were in Asia. However, in the future this problem might be expected to be even more widespread. The graphs below show some predictions of future scenarios regarding flooding, drought and crop yield, each of which would suggest that people may be forced to migrate.
- Future change in flood frequency. Source: Shah, 2014.
- Future changes in drought. Source: Shah, 2014.
- Future changes in crop yields. Source: Shah, 2014.
Furthermore, the issue of migration will be most severe for concentrated populations that currently live in cities. The growth of cities has been strongest in Asia where already around half of the world’s population live. As most of these large Asian cities are coastal, significant problems may arise if populations are forced to move away.
- Urbanisation, migration and climate. Source: ODI/UNDP, 2017.
This is reinforced by the graphic below showing China’s problems with water supplies, flooding, typhoons and agriculture. If this scenario occurs, the Chinese government may need to move even more people to its already overcrowded eastern seaboard.
- Possible Chinese migration due to climate change. Source: Fernandez, 2017.
The poorest will not migrate
In general it might be expected that the poorest people will be the first to migrate. This is because they will struggle to meet their basic needs when either income is taken away (due to e.g. lower yields) or their expenses rise (due to e.g. the need to replace a house after a flood). This can be described as their ‘incentive’ to move.
However, the very poorest may find that climate change decreases their available resources so much that they can’t afford to migrate, i.e. they are so poor that they can’t move. Cattaneo and Peri’s 2015 research paper found that the main indicator of future climate change migration isn’t the extent or impacts of climate change, but a person’s level of income. If people have a middle income they will migrate; if a person is on a very low income, the “potential migrants have a reduced ability to pay for migration costs and to afford travel and relocation costs” (Cattaneo, 2015), as shown on the graphs below.
- Emigration rates and temperature change for middle income and poor countries between 1960 and 2000 for 116 countries. Source: Cattaneo, 2015.
They also looked at the places people migrated to, and identified a key conclusion:
“We find that growing temperatures are mainly associated with emigration to non-OECD destinations that are close to the countries of origin (especially those within a 1,000km radius). Emigration to OECD (i.e. rich) countries does not seem affected.” (Cattaneo, 2015)
This means that richer countries do not need to expect a rush of migration in the future; rather, people will migrate to a nearby location that is less affected by climate change.
Cattaneo, 2015. How does climate change affect migration? https://www.weforum.org/agenda/2015/11/how-does-climate-change-affect-migration/ Accessed 28 February 2018.
Fernandez, 2017. Climate change will force mass migration of 1 billion by 2100. http://www.eco-business.com/news/climate-change-will-force-mass-migration-of-1-billion-by-2100/ Accessed 28 February 2018.
ODI/UNDP [Overseas Development Institute and United Nations Development Programme], 2017. Climate Change, Migration and Displacement: The need for a risk-informed and coherent approach. https://resourcecentre.savethechildren.net/library/climate-change-migration-and-displacement-need-risk-informed-and-coherent-approach Accessed 28 February 2018.
Shah, 2014. What will the world look like in 2100? http://www.eco-business.com/news/what-will-world-look-like-2100/ Accessed 28 February 2018.
UNFCCC, 2018. New Data Brings New Answers on Climate Migration. http://newsroom.unfccc.int/unfccc-newsroom/human-mobility-and-the-paris-agreement/ Accessed 28 February 2018.
Societal impacts of climate change: Migration: Learning activities
- Outline the range of reasons why people are displaced from their homes in the world today. 
- Describe and explain the distribution of the top displacement events of 2016. 
- Using the map sources only, identify the areas of the world which you think will have the most out-migration due to climate change in the future. 
- Suggest why your answer to Question 3 might be contested. Use the graph from Cattaneo (2015) to help you. 
Produce a presentation about this issue to show to a non-specialist. Anticipate the questions they might have and ensure that key terminology is clearly explained.
© Matthew Burdett, 2018. All rights reserved.
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