Transcript ubcm - Thomas Homer

Climate Change and Municipalities
in Canada:
Mitigation and Adaptation
Thomas Homer-Dixon
Trudeau Centre for Peace and Conflict Studies
University of Toronto
September 26 2007
• Climate change, some basic
science
• Consequences
• Responses at municipal level
BASIC SCIENCE
Take-away messages:
• Earth is warming quickly
• Humans are the main cause
• Warming will be most pronounced at
high latitudes and on land
• Future warming will be nonlinear
because of feedbacks
Direct Observations of Recent Climate Change
Warming of the climate system is unequivocal, as is
now evident from observations of increases in global
average air and ocean temperatures, widespread
melting of snow and ice, and rising global mean sea
level.
More rapid warming at poles
Main reason: Ice-albedo feedback
Melting of ice 
Lower reflectivity 
Increased absorption of sun’s
energy 
Melting of ice
Sept. 16
4.12 million km2
Projections of Future Changes in Climate
Best estimate for
low scenario (B1)
is 1.8°C (likely
range is 1.1°C to
2.9°C), and for
high scenario
(A1FI) is 4.0°C
(likely range is
2.4°C to 6.4°C).
Projections of Future Changes in Climate
Projected warming
in 21st century
expected to be
greatest over land
and at most high
northern latitudes
and least over the
Southern Ocean
and parts of the
North Atlantic
Ocean
0.25
Ice Accumulation Rate
(meters per year)
0.2
0.15
0.1
0.05
0
13000
12500
12000
11500
Years before Present
11000
10500
CONSEQUENCES
Take-away messages:
• Extreme events will become more
frequent
• Climate change will interact
synergistically with other stresses and
vulnerabilities
Rising Frequency of Extreme Events
Frequency
of event
Severity of Event
Rising Frequency of Extreme Events
Frequency
of event
Y1
X
Severity of Event
Rising Frequency of Extreme Events
Y2
Frequency
of event
Y1
X
Severity of Event
RESPONSES
Municipalities need to mitigate
and
adapt
Potential Impact
Impact, Mitigation, and Adaptation
mitigation
adaptation
realized impact
2000
2050
2100
Chris Milly (USGS/NOAA-GFDL, 2007)
The Challenge: Very soon, humankind must cap—
and then ramp down—global carbon emissions
We have very little “room to warm”:
Estimated maximum “safe” warming: 2°C
Warming to date: 0.8°C
Warming in pipeline, even if emissions cease: 0.6°C
Room to warm: 0.6°C
So we have very little “room to emit”:
Estimated carbon concentration that is likely to
produce at least 2°C warming: ~450 ppm
Current concentration: ~380 ppm
Room to emit: ~ 70 ppm
Incremental annual increase: ~2 ppm and rising
Years to 450 ppm: ~ 30
CALGARY’S TARGET 50 PLAN
•Increasing our use of Green Power
•Capturing methane from landfills for energy
use
•Greening our vehicle fleet
•Improving the energy efficiency of buildings
& facilities
•Conserving water and energy in our facilities
•Demonstrating new & innovative
technologies & practices
RESPONSES
Municipalities need to act in four
areas:
• Overall planning
• Infrastructure
• Facilities
• Emergency preparedness
PLANNING CONSIDERATIONS
• Population density
• Transport
• Vegetation, landscaping
• Disease and pests that affect
humans, plants, and livestock
INFRASTRUCTURE
• Water
• Energy
• Sewers
FACILITIES
• Schools
• Seniors’ homes
• Hospitals
• Parks and recreation facilities
EMERGENCY PREPARATION
• Flood
• Drought
• Heat waves
• Blackouts
FINAL ADVICE
• Be creative
• Challenge standard operating
procedures
• Work with civil society
• Plan long
• Remember your grandchildren