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, 2007
McLeman et al 2007
Levels of adaptation
Actor/scale
Type of adaptation
• Governance/
institutions
• Technological
improvements
• Programs/subsidies
• Individual farm
• Modify farming
practices
• Non-farming
adaptations
after Smit and Skinner 2002
1930s Oklahoma droughts
Actor/scale
Type of adaptation
• Governance/
institutions
• Technological
improvements
• Programs/subsidies
• Individual farm
• Modify farming
practices
• Non-farming
adaptations
1930s Oklahoma droughts
• Adaptation options constrained by access
to economic, social, cultural capital
• Particular types of capital facilitated outmigration 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
CANADA
Ontario
ONTARIO
Ottawa
Addington
Highlands
Toronto
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 microbursts (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
85 years and over
80 to 84
75 to 79
70 to 74
65 to 69
Number of People
60 to 64
55 to 59
50 to 54
45 to 49
Female
40 to 44
Male
35 to 39
30 to 34
25 to 29
20 to 24
15 to 19
10 to 14
5 to 9
0 to 4
150
100
50
0
50
100
150
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 climatemigration
• Building GIS model to combine climate &
demographic data to identify “hotspots’
• Start with western Canada – droughtrelated 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