Climate change, environmental

degradation and migration: how

viable are current predictions?

Dr Dominic Kniveton

“Pressure to migrate

will intensify”“1bn likely to be

displaced by 2050”

“150-200 million

environmental

refugees by the

middle of the

century”

Future floods of refugees?

Estimates of numbers are ‘at best, guesswork’ (IPCC,

2007)

The nexus between climate change, environmental

degradation and migration has not been explored

empirically in a way that generates conclusive

results.

Migration patterns

• Intra-regional movement > overseas movement

• Internal migration > intra-regional movement

• Drivers include ‘push’ and ‘pull’ factors

– Push: political instability, conflict, lack of economic opportunities, lack of access to resources, climate variability and stocks

– Pull: employment and demand for workers, higher wages in destination regions, kin and social networks

• Intervening factors: – Include immigration/registration policies, transport

infrastructure, cultural networks and aid policies

Top down approach

• Past estimates identify areas affected by

environmental and climate change, count the

number of people living there, and use this to

estimate the number likely to be forced to leave

• Neglects to account for the specific local contexts

and multiple factors that underpin migratory

decisions

Burkina Faso

• Drought associated with decreases in international, long-distance migration

• Food scarcity during drought leads to increased prices, forcing people to spend more money on their basic needs rather than on long-distance migration

• Short-distance migration to larger agglomerations increased during drought years, as women and children left in search of work to contribute to household incomes.

Henry, S., Schoumaker, B. and Beauchemin, C., 2004, Population and

Environment, Vol. 25, No. 5, pp. 423-60

El Salvador

• Loss of harvest and livestock increased the household’s probability of sending members to the United States

• But earthquakes were associated with a substantial decrease in net migration to the US

Halliday, T. 2006, Economic Development and Cultural Change, Vol. 54, No. 4, pp. 893-925.

‘Bottom-up’ vulnerability and adaptation

assessments

• Start at the local scale by addressing socio-economic responses to climate, which tend to be location-specific.

• However these often fail to account for both individual and collective definitions of what constitutes a dangerous climatic

or environmental risk that may initiate migration

Lack of data

• Lack of time-sensitive migration flow data

such that change in climate and other factors

at time t can be used to explain migration at

time t+1.

• This shortage of data is particularly acute for

internal movements of people

Climate change and uncertainty

Rainfall trendsRainfall trendsRainfall trendsRainfall trends

Multi-model averages; A1B scenario

Stippled areas: >90% models agree on

sign change

December – February June – August

• A number of projected

future climate changes

are predicted to be of a

magnitude and

variability unlikely to be

experienced by

communities in the past.

• This restricts the use of

statistical models and

historical analogues to

extrapolate future

climate-migration

impacts.

Negative impact or adaptative strategy?

• In the past migration has largely been seen as a response to climate change, and thus as a negative impact of climate change.

• Ignores the idea of migration as an adaptativestrategy that increases household resilience to negative climate change impacts and may exclude important future migration flows of people attempting to benefit from some of the positive impacts of climate change .

• Existing overviews of environmental and climate change and migration flawed

• Problem of multiple causation, push and pull

• Relative lack of empirical material

• Some studies show declining migration in response to drought

• Likely continued migration to zones at risk of flooding

• Alternative approaches: explore sensitivity of existing migration flows to climate change and agent based simulation of migration decision making process

Summary