Climate Change Climate Change and Forest Fire and Forest Fire

Activity in CanadaActivity in Canada

B.J. Stocks, M.D. Flannigan, B.M. Wotton, B.D. B.J. Stocks, M.D. Flannigan, B.M. Wotton, B.D. Amiro, and J.B. ToddAmiro, and J.B. Todd

Natural Resources Canada – Canadian Forest ServiceNatural Resources Canada – Canadian Forest Service

Presentation to Senate Standing Committee on Agriculture and ForestryApril 10, 2003Ottawa, Ontario

Circumboreal Forest Circumboreal Forest Fire ActivityFire Activity

• Annual burned area: 5-15 million Annual burned area: 5-15 million hectareshectares

• Primarily Canada, Russia and Primarily Canada, Russia and AlaskaAlaska

• Russian stats underestimated – Russian stats underestimated – should be 5 to 10 times highershould be 5 to 10 times higher

• Area burned shows great inter-Area burned shows great inter-annual variabilityannual variability

• Continental climate, extreme Continental climate, extreme weather/fire danger conditions, weather/fire danger conditions, multiple ignitions, and closed multiple ignitions, and closed canopy forests are main drivers canopy forests are main drivers of boreal fire activityof boreal fire activity

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

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1997

1998

1999

ALASKA

CANADA

0

1

2

3

4

5

6

7

8

Area

Bur

ned

( 10

6 ha

)

Annual Area Burned 1980-1999

ALASKA

RUSSIA

CANADA

Boreal Fire Boreal Fire Importance/CharacteristicsImportance/Characteristics

• Dominant disturbance regime, natural & essential to Dominant disturbance regime, natural & essential to ecosystem maintenance, C cycling, biodiversityecosystem maintenance, C cycling, biodiversity

• Sensitive to climate change – major carbon budget Sensitive to climate change – major carbon budget implications - 40% of terrestrial C in boreal zoneimplications - 40% of terrestrial C in boreal zone

• High fuel consumption, fast spread rates, sustained high High fuel consumption, fast spread rates, sustained high intensity levels, towering convection columns (upper intensity levels, towering convection columns (upper troposphere) with long-range smoke transport potentialtroposphere) with long-range smoke transport potential

Canadian Fire Canadian Fire StatisticsStatistics

• Incomplete prior to 1970Incomplete prior to 1970• < certainty further back in time< certainty further back in time• Now 8000 fires, 2.8 million ha/yrNow 8000 fires, 2.8 million ha/yr• $500 million annually$500 million annually• Area burned is highly episodic Area burned is highly episodic

0.7 to 7.6 million ha0.7 to 7.6 million ha• Level of protection issueLevel of protection issue

Protect resources vs natural fireProtect resources vs natural fire• Lightning fires Lightning fires

35% of total fires /85% AB35% of total fires /85% AB• Fire sizeFire size

3% of fires are >200 ha (used in 3% of fires are >200 ha (used in Large Fire Database)Large Fire Database)

Remainder suppressed earlyRemainder suppressed early Represent 97% of area burnedRepresent 97% of area burned

Large Fire Database (LFDB)Large Fire Database (LFDB)• Fires >200 ha post-1950 nationallyFires >200 ha post-1950 nationally• Polygons with attributes (fire size, cause, start Polygons with attributes (fire size, cause, start

and end dates etc.) from fire management and end dates etc.) from fire management agenciesagencies

• 1980s fires in central Canada illustrated1980s fires in central Canada illustrated• Updated annually – working back in time with Updated annually – working back in time with

satellite imagerysatellite imagery

Lightning/Human-Caused FiresLightning/Human-Caused Fires

Most lightning fires in north, H-C along travel corridorsMost lightning fires in north, H-C along travel corridors Generally lightning fires grow larger – detection/access Generally lightning fires grow larger – detection/access

issueissue Lightning fire contribution to area burned increasing in Lightning fire contribution to area burned increasing in

recent decadesrecent decades

Hum an- vs. Lightning-Caused Fires by Decade

0

5

10

15

20

25

30

1959-69 1970-79 1980-89 1990-99

Years

Are

a B

urn

ed (

x10

6 h

a) Lightning

Human

Actioned/Non-Actioned FiresActioned/Non-Actioned Fires

Many fires allowed to burn naturally, mainly in northMany fires allowed to burn naturally, mainly in north Management decision based on values-at-risk Management decision based on values-at-risk Constitutes ~50% of area burned in Canada post-1959Constitutes ~50% of area burned in Canada post-1959

LFDB Fire Size Distribution by Ecozone

All Ecozones

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

1 2 3 4 5 6 7 8 9

Size Class

Perc

en

t

Area Burned No. of Fires

Greatest area burned in boreal and taiga zones of west-central Canada where unsuppressed fire is common andfire climate most severe

Larger size-class fires, although lessfrequent, account for most of area burned

Carbon Release Through FireCarbon Release Through Fire• Direct release to atmosphere averages 27 Tg C/yr (20% Direct release to atmosphere averages 27 Tg C/yr (20%

of Canada’s fossil fuel emissions) - preliminary estimate of Canada’s fossil fuel emissions) - preliminary estimate - need further severity/decomposition work- need further severity/decomposition work

• Younger forests weaker C sinks than mature forestsYounger forests weaker C sinks than mature forests• Takes 20-30 years to fully recover after fire (confirmed Takes 20-30 years to fully recover after fire (confirmed

from flux tower, aircraft and satellite measurements)from flux tower, aircraft and satellite measurements)

Canadian Direct Carbon Emissions

0

20

40

60

80

100

120

140

160

1958

1960

1962

1964

1966

1968

1970

1972

1974

1976

1978

1980

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1998

2000

Year

Meg

ato

nn

es C

arb

on

Fire

Fossil Fuel

Disturbances and the Carbon Disturbances and the Carbon BudgetBudget

02468

10

1920 1940 1960 1980 2000

Are

a (M

illi

on h

a)

ClearCut Fire Insects Total

-200-100

0

100

200300

400

1920 1940 1960 1980 2000

Tg

C /

yr

Variable Temp Constant Temp

Source

SinkNote change after 1970

Note rise in natural disturbances (fire and insects) post 1970

Corresponding decrease in C sink strength of CDN forest post-1970

Anticipated Changes in Seasonal Fire Danger and Fire Season Length

Fire season length increases by 10 to 50 days by 2090

Seasonal fire danger increases by 50-100% by 2090

• Increase in weather conditions conducive to fires Increase in weather conditions conducive to fires

• More frequent and severe fire activityMore frequent and severe fire activity• Projected impacts:Projected impacts:

More area burned, shorter fire return intervalsMore area burned, shorter fire return intervals Younger age class structureYounger age class structure Ecosystem boundary/vegetation shiftingEcosystem boundary/vegetation shifting Less terrestrial C storageLess terrestrial C storage Impacts on forest industry/communitiesImpacts on forest industry/communities Health/pollution issuesHealth/pollution issues

• Positive feedback to climate change (>GHG Positive feedback to climate change (>GHG emissions)emissions)

• Need to quantify impacts in order to assess optionsNeed to quantify impacts in order to assess options• Adaptation will be requiredAdaptation will be required• Ongoing CFS climate change/fire research addressing Ongoing CFS climate change/fire research addressing

impacts and adaptation in collaboration with impacts and adaptation in collaboration with provinces/territoriesprovinces/territories

• Funding through Green Plan, Climate Change Action Funding through Green Plan, Climate Change Action Fund, Action Plan 2000 and CRAs with provincesFund, Action Plan 2000 and CRAs with provinces

Anticipated Fire ImpactsAnticipated Fire Impacts

Adapting to Increasing Fire Adapting to Increasing Fire ActivityActivity

• Local scale:Local scale:• Community protection (FIRESMART)Community protection (FIRESMART)

• Regional scale:Regional scale:• Pilot fuelbreaks project – break up fuel Pilot fuelbreaks project – break up fuel

continuity to limit fire effects on fiber continuity to limit fire effects on fiber productionproduction

• Level of protection effectiveness studies – Level of protection effectiveness studies – cost of maintaining status quo with cost of maintaining status quo with increasing risk, protect less and permit increasing risk, protect less and permit more natural firemore natural fire

• National scale:National scale:• Cannot mitigate fire impacts across whole Cannot mitigate fire impacts across whole

boreal forestboreal forest• Adapt based on values-at-riskAdapt based on values-at-risk• Evaluate the impacts of an increased fire Evaluate the impacts of an increased fire

regime for policy-makersregime for policy-makers

Questions?