Climate change and adaptive human migration Dr. Robert McLeman Department of Geography University of...

Climate change and adaptive human migration

Dr. Robert McLeman

Department of Geography

University of Ottawa

Theoretical & conceptual backdrop

• Migration is but one way by which households may adapt to climate-related stress

• Is not simple stimulus-response process

• Household adaptation options and migration decisions are condition by access to capital

McLeman and Smit 2006

Empirical work

• Highlights from 3 projects

Project 1: Migration vs. other household adaptation options

• Oklahoma 1930s

• Severe droughts, crop failures

McLeman 2006, 2007McLeman et al 2007

Levels of adaptation

Actor/scale

• Governance/ institutions

• Individual farm

Type of adaptation

• Technological improvements

• Programs/subsidies

• Modify farming practices

• Non-farming adaptations

after Smit and Skinner 2002

1930s Oklahoma droughts

Actor/scale

• Governance/ institutions

• Individual farm

Type of adaptation

• Technological improvements

• Programs/subsidies

• Modify farming practices

• Non-farming adaptations

came too late

too costly

already at maximum

1930s Oklahoma droughts

• Adaptation options constrained by access to economic, social, cultural capital

• Particular types of capital facilitated out-migration by young, skilled families

• Feedback effects on adaptive capacity

• Drought areas lost human capital, social cohesion

McLeman et al 2007

Project 2: Demographic change and community adaptive capacity

Toronto

Ottawa

ONTARIO

CANADA

Ontario

AddingtonHighlands

www.addington.uottawa.ca

Observed climatic changes in Addington Highlands

• Shorter, milder winters with less snow

• Earlier spring conditions

• Warmer summers with less variability

• Increasingly windy with occasional micro-bursts (short, high-intensity windstorms)

Demographic change

• Population = 2,500

• Absolute numbers unchanged from 1901

• But…

Demographic change

• Population = 2,500

• Absolute numbers unchanged from 1901

• But… 2006 Population

150 100 50 0 50 100 150

0 to 4

5 to 9

10 to 14

15 to 19

20 to 24

25 to 29

30 to 34

35 to 39

40 to 44

45 to 49

50 to 54

55 to 59

60 to 64

65 to 69

70 to 74

75 to 79

80 to 84

85 years and overN

um

ber

of

Peo

ple

Female

Male

Impacts on adaptive capacity

Risks

• Pressure on health & emergency services

• Fewer people with survival skills

• Social cohesion breaking down

Opportunity

• Skills of newcomers untapped

Project 3: Modeling climate-migration

• Building GIS model to combine climate & demographic data to identify “hotspots’

• Start with western Canada – drought- related migration known to have occurred

• Can we model to local scale areas where severe drought & population decline coincided?

McLeman et al. submitted

Datasets

• Canada census data 1926, 1931, 1936

• Historical climate model data at 10km2 grid cells (McKenny et al. 2006)

• Summer monthly temperature and precipitation data selected for 1926-36

• Organized according to cumulative frequency of relatively hot, dry conditions

Population change 1931-36

Average summer precipitation 1926-36

Average summer temperatures 1926-1936

Combined data sets, 1931-36

Population decline exceeding 10% 1931-36

Thanks!

Dr. Robert McLeman

Assistant Professor

Department of Geography

University of Ottawa

Canada K1N 6N5

rmcleman@uottawa.ca