WhatWhat’’s Happening, and Whats Happening, and What

Can We ExpectCan We Expect

GLOBAL CLIMATE CHANGE:GLOBAL CLIMATE CHANGE:

What is ‘climate’?

•Climate is ‘average weather’- and its variability- for a particular region- over a period of time

•Includes many different elements

What is ‘climate change’?

•Climate change is a shift in ‘climate’ relative to agiven reference time period

•It is caused by:

Natural factors

-Solar variability-Volcanic dust levels

-Internal variability -Geological change

- Greenhouse gases - Aerosols -Ozone depletion

-Land use change

Human factors

The earth’s atmosphere consists of multiplelayers

…and provides several important life supporting services

Protection from solar uv-b(stratospheric ozone)

surface

stratosphere

thunderstormtroposphere

The air we breath (21% oxygen)

Suitable, stableclimateand weather

Reflected Energy

Incoming Energy

Outgoing Energy

Energy TrappedBy Greenhouse Gases

Incoming solar energy heats the Earth, and outgoing heat radiation cools it off

Water

Vapour

OtherCarbon

Dioxide

~65%

~25% ~10%

Primary Contributors to theNatural Greenhouse Effect

MarsAtmosphere: mass <1% earth’s

GH Gases: >80% CO2

Sfc. Temp.: -47°C

GH Effect: 10°C

FAR TOO COLD!

Other planets also have Greenhouse Effects, but these are unsuitable for life

EarthGH Gases: ~0.04% CO2

~ 1% H2O

Sfc. Temp.: 15°C

GH Effect: 33°C

NOT BAD!

Venus

Atmosphere: mass 90x earth’s

GH Gases: >90% CO2

Sfc. Temp.: 477°C

GH Effect: 523°C

FAR TOO HOT!

Sun

Latitudinal differences in net energy balance causeatmosphere and ocean circulation

However, the climate system is also influenced bymany other complex interactions and feedbacks

““Humanity is conducting anHumanity is conducting anunintended, uncontrolled, globallyunintended, uncontrolled, globally

pervasive experiment whose ultimatepervasive experiment whose ultimateconsequences could be second only toconsequences could be second only to

a global nuclear war.a global nuclear war.””

World Conference onWorld Conference on

The Changing Atmosphere:The Changing Atmosphere:

Toronto, June 1988Toronto, June 1988

Greenhouse Effect

Disaster

Junk Science!

KyotoFramework Convention

on Climate Change

IPCC

I Love Global Warming

I Love Global Warming!

Everyone seems to be talking about

climate change - but confusion reigns!

“The climate system is anangry beast and we arepoking at it with sticks!”

Wallace Broecker

Year

Billio

n t

on

nes o

f carb

on

per

year

(GtC

/yr)

Fossil fuelemissions

Land use changeemissions

Carbon dioxide emissions from humansources have increased steadily over thepast century

Temperature patterns will change substantially

by 2050 Annual mean

Winters 2080-2100

By 2090, winter temperatures in most of Canadacould rise by 5 to 15 degrees or more

Summers 2080-2100

…and summer temperatures by 4 to 10 degrees

There is a small but finite risk of collapse of theWest Antarctic Ice Sheet

4-6 meter sea levelrise!

Ecological systems are sensitive toclimate change

• Biological systems have already been affected bychanges in climate.

• The structure and functioning of ecological systemswill be altered and the biological diversity willdecrease.

forests, especially tropical and boreal forests are vulnerable due tochanges (pests and fires)

coral reefs are threatened by increases in temperature, more thanincreases in sea level

Vulnerable species will be increasingly threatenedby changing habitat and food supply

There are also many reasons for concernabout the impacts on humans

• A place to live– sea level rise

– floods

• Food to eat– crop losses in tropical regions

– droughts

• Health– extreme weather

– disease/air quality

• Economic well-being

Changing ice sheets

Receding glaciers

Rising ocean temperatures

Sea levels will rise

Deltaic countries like Bangladesh would beparticularly vulnerable

Today

1 M sea level rise

•20.7% land loss•14.8 million people affected

Other examples of costs of sea level rise:

• Impacts

– for 0.5 m rise

• 32% of urban Egypt property flooded, loss of US$ 35 B

• $20 to 150 billion property loss in the USA

– for 1 m rise

• 17 million people directly affected by flooding in Vietnam

• US$410 property loss in Germany

• Protection Costs

– for 1 m rise,

• ~US$30 B for Germany

• For 1 m rise, ~$200 B for Japan

Inland flood disasters may become more frequent as rains become more intense

• Up to 3 billion additionalpeople stressed by watershortages

Decreased water supply in many parts of theworld is a major concern

The health of many people will be affected

• Diseases

• Heat

• Weather disasters

• Air and water quality

Potential impacts of climate change on Canada

Atlantic CanadaOntario and Quebec

The North

The Prairies

British

Columbia

Potential benefits to Canadians include:

Lower snow removal costs

Less ice coveron Great Lakesand along east coast

Longer, warmer growing seasons

In P.E.I., the current

100 year storm surge

could occur once per

decade by

2100

Rising sea levels are already eroding P.E.I.shorelines

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LocalSeaLevel rise

……and Quebecand Quebec’’s coastals coastal

cliffscliffs

West Nile Virus

Lyme Disease

There are also risks of the spread of diseases

Game of Chance Analogy Probability

1 in 6

1 in 36

1 in 216

1 in 1296

In some ways, the risks of extreme events arelike the odds in games of chance

Extreme events can cause many types of disasters

Lightning damage Floodlosses

Ecologicaldisaster

Structural damage

Wind damage

Loss oflife

Canada’s coastal fisheries will be affected bychanges in species distribution

Ecological preserves within the national parksmay be at risk

The related increase in land instability may havelarge impacts on human structures

such as buildings

roads

and pipelines

Warmer winters will also reduce the reliabilityof winter roads

Winter Road, Norman Wells

…on frozen wetlands

Ice Road, Tuktoyaktuk

…or on frozen lakes and rivers

BenefitsBenefitsAdverseAdverse

ImpactsImpacts

The net economic effect may be small if changeis modest

BenefitsBenefits

AdverseAdverse

ImpactsImpacts

…but could become very costly if the change israpid or large

Some economic considerationsfor Canada

• Between 20 and 60% of GDP is sensitive to thechanges in weather and climate

• Between 1985 and 1999, extreme weather eventscaused Canadian economic losses of more than$14 billion, and 240 deaths

Winnipeg floodwayCost today: $330 million

Old Man River Damcost in 1990: $430 million

Adaptation works

“To survive in the

world we have

transformed, we

must learn to think

in a new way. As

never before, the

future of each

depends on the

good of all.”

100 Nobel Laureates

Oslo, December 2001