Climate Change and Forest Fire Activity in Canada

1. Climate Change and Forest Fire Activity in Canada B.J. Stocks, M.D. Flannigan, B.M. Wotton, B.D. Amiro, and J.B. Todd Natural Resources Canada – Canadian Forest Service Presentation to Senate Standing Committee on Agriculture and Forestry April 10, 2003 Ottawa, Ontario

2. Circumboreal Forest Fire Activity • Annual burned area: 5-15 million hectares • Primarily Canada, Russia and Alaska • Russian stats underestimated – should be 5 to 10 times higher • Area burned shows great inter-annual variability • Continental climate, extreme weather/fire danger conditions, multiple ignitions, and closed canopy forests are main drivers of boreal fire activity

3. Boreal Fire Importance/Characteristics • Dominant disturbance regime, natural & essential to ecosystem maintenance, C cycling, biodiversity • Sensitive to climate change – major carbon budget implications - 40% of terrestrial C in boreal zone • High fuel consumption, fast spread rates, sustained high intensity levels, towering convection columns (upper troposphere) with long-range smoke transport potential

4. Canadian Fire Statistics • Incomplete prior to 1970 • < certainty further back in time • Now 8000 fires, 2.8 million ha/yr • $500 million annually • Area burned is highly episodic • 0.7 to 7.6 million ha • Level of protection issue • Protect resources vs natural fire • Lightning fires • 35% of total fires /85% AB • Fire size • 3% of fires are >200 ha (used in Large Fire Database) • Remainder suppressed early • Represent 97% of area burned

5. Large Fire Database (LFDB) • Fires >200 ha post-1950 nationally • Polygons with attributes (fire size, cause, start and end dates etc.) from fire management agencies • 1980s fires in central Canada illustrated • Updated annually – working back in time with satellite imagery

6. Lightning/Human-Caused Fires • Most lightning fires in north, H-C along travel corridors • Generally lightning fires grow larger – detection/access issue • Lightning fire contribution to area burned increasing in recent decades

7. Actioned/Non-Actioned Fires • Many fires allowed to burn naturally, mainly in north • Management decision based on values-at-risk • Constitutes ~50% of area burned in Canada post-1959

8. LFDB Fire Size Distribution by Ecozone Greatest area burned in boreal and taiga zones of west-central Canada where unsuppressed fire is common and fire climate most severe Larger size-class fires, although less frequent, account for most of area burned

9. Carbon Release Through Fire • Direct release to atmosphere averages 27 Tg C/yr (20% of Canada’s fossil fuel emissions) - preliminary estimate - need further severity/decomposition work • Younger forests weaker C sinks than mature forests • Takes 20-30 years to fully recover after fire (confirmed from flux tower, aircraft and satellite measurements)

10. Disturbances and the Carbon Budget 10 8 6 Area (Million ha) 4 2 400 Note change after 1970 0 Sink 1920 1940 1960 1980 2000 300 200 100 Tg C / yr ClearCut Fire Insects Total 0 -100 Source -200 1920 1940 1960 1980 2000 Variable Temp Constant Temp Note rise in natural disturbances (fire and insects) post 1970 Corresponding decrease in C sink strength of CDN forest post-1970

11. 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

12. Anticipated Fire Impacts • Increase in weather conditions conducive to fires • More frequent and severe fire activity • Projected impacts: • More area burned, shorter fire return intervals • Younger age class structure • Ecosystem boundary/vegetation shifting • Less terrestrial C storage • Impacts on forest industry/communities • Health/pollution issues • Positive feedback to climate change (>GHG emissions) • Need to quantify impacts in order to assess options • Adaptation will be required • Ongoing CFS climate change/fire research addressing impacts and adaptation in collaboration with provinces/territories • Funding through Green Plan, Climate Change Action Fund, Action Plan 2000 and CRAs with provinces

13. Adapting to Increasing Fire Activity • Local scale: • Community protection (FIRESMART) • Regional scale: • Pilot fuelbreaks project – break up fuel continuity to limit fire effects on fiber production • Level of protection effectiveness studies – cost of maintaining status quo with increasing risk, protect less and permit more natural fire • National scale: • Cannot mitigate fire impacts across whole boreal forest • Adapt based on values-at-risk • Evaluate the impacts of an increased fire regime for policy-makers

14. Questions?