Climate Change and Municipalitiesin Canada:

Mitigation and Adaptation

Thomas Homer-Dixon

Trudeau Centre for Peace and Conflict Studies

University of Toronto

September 26 2007

• Climate change, some basicClimate change, some basicsciencescience

• ConsequencesConsequences

• Responses at municipal level Responses at municipal level

BASIC SCIENCEBASIC SCIENCE

Take-away messages:Take-away messages:• Earth is warming quicklyEarth is warming quickly

• Humans are the main causeHumans are the main cause

• Warming will be most pronounced at Warming will be most pronounced at high latitudes and on landhigh latitudes and on land

• Future warming will be nonlinearFuture warming will be nonlinear because of because of feedbacksfeedbacks

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.

Direct Observations of Recent Climate Change

More rapid warming at polesMore rapid warming at poles

Main reason: Ice-albedo feedbackMain reason: Ice-albedo feedback

Melting of ice Melting of ice Lower reflectivity Lower reflectivity Increased absorption of sun’sIncreased absorption of sun’s energy energy Melting of iceMelting of ice

Sept. 164.12 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).

Projected warmingin 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

Projections of Future Changes in Climate

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Years before Present

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CONSEQUENCESCONSEQUENCES

Take-away messages:Take-away messages:

• Extreme events will become more Extreme events will become more frequentfrequent

• Climate change will interact Climate change will interact synergistically with other stresses and synergistically with other stresses and vulnerabilitiesvulnerabilities

Rising Frequency of Extreme EventsRising Frequency of Extreme Events

Severity of Event

Frequencyof event

Rising Frequency of Extreme EventsRising Frequency of Extreme Events

Severity of Event

Frequencyof event

X

Y1

Rising Frequency of Extreme EventsRising Frequency of Extreme Events

Severity of Event

Frequencyof event

X

Y1

Y2

RESPONSESRESPONSES

Municipalities need to Municipalities need to mitigatemitigate

andand

adaptadapt

Impact, Mitigation, and AdaptationImpact, Mitigation, and Adaptation

2000 2100

Pot

entia

l Im

pact

2050

realized impact

mitigation

adaptation

Chris Milly (USGS/NOAA-GFDL, 2007)

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

The Challenge: Very soon, humankind must cap—

and then ramp down—global carbon emissions

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

•Increasing our use of Green PowerIncreasing our use of Green Power

•Capturing methane from landfills for energy Capturing methane from landfills for energy useuse

•Greening our vehicle fleetGreening our vehicle fleet

•Improving the energy efficiency of buildings Improving the energy efficiency of buildings & facilities & facilities

•Conserving water and energy in our facilitiesConserving water and energy in our facilities

•Demonstrating new & innovative Demonstrating new & innovative technologies & practices technologies & practices

CALGARY’S TARGET 50 PLAN

RESPONSESRESPONSES

Municipalities need to actMunicipalities need to act in four in four areas:areas:

• Overall planningOverall planning

• InfrastructureInfrastructure

• FacilitiesFacilities

• Emergency preparednessEmergency preparedness

PLANNING CONSIDERATIONSPLANNING CONSIDERATIONS

• Population densityPopulation density

• TransportTransport

• Vegetation, landscapingVegetation, landscaping

• Disease and pests that affect Disease and pests that affect humans, plants, and livestockhumans, plants, and livestock

INFRASTRUCTUREINFRASTRUCTURE

• WaterWater

• EnergyEnergy

• SewersSewers

FACILITIESFACILITIES

• SchoolsSchools

• Seniors’ homesSeniors’ homes

• HospitalsHospitals

• Parks and recreation facilitiesParks and recreation facilities

EMERGENCY PREPARATIONEMERGENCY PREPARATION

• FloodFlood

• DroughtDrought

• Heat wavesHeat waves

• BlackoutsBlackouts

FINAL ADVICEFINAL ADVICE

• Be creativeBe creative

• Challenge standard operating Challenge standard operating proceduresprocedures

• Work with civil societyWork with civil society

• Plan longPlan long

• Remember your grandchildrenRemember your grandchildren