Human migration in the era of climate change Cristina Cattaneo - - PowerPoint PPT Presentation

Human migration in the era of climate change 5th MEDENER International Conference on Energy Transition 30 November 2017, Lisbon Cristina Cattaneo (FEEM)

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• Archeological evidence: periods of drastic climatic change

coincided with the collapse of past civilizations

• Urban centers of the Harrapan Society in the Indus Valley,

were abandoned during a 200-year drought that

• ccurred 4000 years ago
• American Dust Bowl in ‘30s: Hundreds of thousand families

abandoned large areas of American Plains as a consequence of the large dust storms and desertification process

Historic migration as adaptation

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• Migration is multicausal: climate change is one of

the five drivers

Environmental

factors alone rarely lead to migration

• Environmental drivers may also influence the other

drivers

Economic

drivers: reduction in agricultural productivity (increase income differentials) or increase in agricultural risks (income variability)

Political drivers: conflicts

Drivers of migration

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Drivers of migration

Source: Black et al. (2011) “Climate change: Migration as adaptation“, Nature

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• Temporary and return migration
• Permanent
• Short Distance
• Long Distance and International
• Involuntary and forced

Various forms of migration

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• Migration resulting from fast extreme events

(storms, hurricanes, heavy rains and floods)

• Migration resulting from slow events (drought,

desertification, long-term gradual changes in temperature and rainfall) Direct versus indirect effects

Various forms of environmental drivers

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• Stark contrast between statements and recent evidence

 “the gravest effects of climate change may be those on human migration as millions will be displaced” IPCC, 1990  The Stern Review suggested that by 2050 there would be 200 million people who would be affected by adverse climate events that could induce migration  The International Organization of Migration (IOM) predicted that up to

• ne billion people could be displaced by environmental causes by

2050

• These

figures are known today for

• verestimating

the phenomenon

• They are treated more as guesstimates than actual evidence

Empirical Evidence (???)

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• Limited evidence that hurricanes, floods provoke long-

term and long-distance migration

• Extreme

climatic events generally produce displacements of limited duration and short distance

• Displacements occur mainly within states (internal

migration) and, to a lesser extent, between neighboring states

• People displaced tend to return to rebuild their homes

as soon as they can

Empirical Evidence: hurricanes, floods

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• The rise in sea levels and coastal erosion are most

likely to trigger definitive and large population movements

• Contrarily to hurricanes, droughts or floods, these

phenomena are irreversible

• With a scenario of an increase of 0.3-0.8 metre of the

sea level, 150 million people living at an altitude of less than one metre are directly vulnerable (South-east Asia; Pacific Islands)

Empirical Evidence: sea level rise

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Empirical Evidence

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• The effect of drought, desertification, gradual changes

in temperature on human mobility is less sudden

• Some examples of mass migration due to drought

 A

million people displaced temporarily

• r

permanently during the drought in Niger in 1985

• Displaced

are relatively small compared to the numbers of people affected by drought

• Sometimes we assist to a reduction in migration

Empirical Evidence: drought, desertification, warming

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Empirical Evidence: immobility

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• Trade-off between higher incentives and lower resources
• Poor people have higher incentives to migrate (most

vulnerable to the impacts of climate change), but lower resources to invest in migration

• Double set of risks
• Trapped populations sometimes face worse humanitarian

crises than migrants

• Trapped populations are typically the most vulnerable
• nes
• Poorest, the least educated, women

Empirical Evidence: immobility

Trapped Population

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Source: Black et al. (2011) “Climate change: Migration as adaptation“, Nature

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• Analysis of the long-run impacts of gradual changes in

temperature and precipitation on international (world- wide) emigration in a panel of 116 countries, classified as poor or middle income, between 1960 and 2000

• Bilateral migration flows between all countries of the

word in the last five available censuses (Ozden et al., 2011)

• Decade average of temperature and precipitation from

weather stations

Empirical Evidence: Cattaneo and Peri (2016)

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• Higher temperatures increased emigration rates to other

countries but only from middle income economies

• In poor countries higher temperatures generate a poverty

trap, that lowers the probability to emigrate to cities or internationally

• Possible pathway is a decline in agricultural productivity:
• Agriculture

productivity and warming is hill-shaped: diminishing net returns to adaptation at the highest temperature

Empirical Evidence: Cattaneo and Peri (2016)

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• Temperature and Emigration: OECD versus non OECD

destinations

• Warming climate increases emigration rates from

middle-income countries

• nly

to non-OECD destinations

• Temperature and Emigration by destination distance
• Higher temperatures increase emigration rates from

middle-income countries only to close destinations (<1000 km)

Empirical Evidence: Cattaneo and Peri (2016)

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• Where climate change increases migration, do climate-migrant

trigger new conflicts or fuel existing ones in receiving countries?

• Climate change may cause large and fast waves of migrants, which

might not be smoothly absorbed in the receiving regions

• Where

climate change reduces migration, do trapped populations increase the risk of conflict in areas of origin?

• Immobility increases population pressure, exacerbates scarcity of vital

resources and this leads to higher risks of conflicts in areas of origin

• Maladaptation or the existence of barriers to migration may represent

an additional source of threats in countries where warming increases social unrest

Indirect effects of climate change: conflicts

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Indirect effects (Bosetti, Cattaneo, Peri)

20 40 60 80 100 6 8 10 12 14 Predicted Inflows of Migrants (natural log)

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Indirect effects (Bosetti, Cattaneo, Peri)

50 100 50 100 10 20 30 10 20 30

Bottom quartile of diaspora Second quartile of diaspora Third quartile of diaspora Top quartile of diaspora

Average temperature

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• No evidence of climate-induced migration’s influence
• n incidence of civil conflicts in destination countries
• In poor origin countries, larger emigration partially

moderates the negative effect of climate change on conflicts

• Lower chances to emigrate increase the negative

effect of warming on conflict Indirect effects (Bosetti, Cattaneo, Peri)

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• The refugee crisis and growing public concern with migration

have seen political upheaval and the rise of populism

• Stark contrast between statements and recent evidence
• Climate-migration is primarily internal, short distance and often
• f limited duration
• Climate-driven migration should not be viewed as an

inevitable catastrophic consequence of climate change

• No reason to expect that Europe will be confronted with massive

waves of “environmental migrants”

• Climate-induced migration should not be perceived as a security

threat

Policy Implications

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• We must look to facilitate migration flows of trapped

populations

• Trapped populations sometimes face worse humanitarian crises than

migrants

• We need to mitigate the impacts of climate change
• People not always move from areas most exposed to the impacts of

climate change to less climate-vulnerable ones

• Facilitate adaptation to climate change through efficiency in

agricultural production

• Improved seeds
• Changing the water supply systems

Policy Implications

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• Development and cooperation policies should aim at

increasing resilience and encourage alternative adaptation strategies

• These policies are often substitute for migration
• Invest in women empowerment to reduce

demographic pressure Policy Implications