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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
1996
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
1982
1984
1986
1988
1990
1992
1994
1996
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