Fire Research » Fire & Climate Change

Fire and Climate Change

General Overview

Fire occurrence and severity in the Canadian forest are driven by levels of moisture within the fuel complex and, as such, are highly sensitive to changes in climate. This interaction between climate and the fire regime has the potential to overshadow the direct effects of global warming on the distribution and migration of forest species. Under current climate change projections, fire frequency and severity can be expected to increase significantly in boreal Canada, with potential major impacts on the global carbon budget. An understanding of the influence of climate change on the occurrence and severity of forest fires is therefore crucial to understanding the impacts of climate change on the Canadian forest.

The program consists of four major components:

• Impact of Global Change in the Boreal Forest
• Effects of Global Biomass Burning on the Carbon Budget
• Assessment of Global Fire Activity Patterns
• Global Fire Monitoring
  

Some important facts:

• How and to what degree the climate is changing is still debatable, but statistics show an increase in fire activity in the past few years. Research is trying to determine if this increase is natural variation, the result of budget constraints, or the first sign of greenhouse effects.
  
  
• Climate has a significant role in the fire regime. Warmer and drier weather leads to more severe fire behavior.
  
  
• Increases in atmospheric moisture could lead to increases in lightning-caused fire ignitions.
  
  
• The concentration of carbon dioxide (CO₂) is commonly used to explain and measure the greenhouse effect. Many global climate models (GCMs) use a double CO₂atmosphere (twice as much CO₂ in the atmosphere than is the case today) as a benchmark for study.
  
  
• Some studies show that a double CO₂ atmosphere may result in an increase in fire severity.
  

Background

Research into the effects of climate change on forest fires in Canada has been under way since the 1980s. The Canadian Forest Service (CFS) Fire Research Network, in collaboration with scientists from around the world, has been studying both the relationship between climate and forest fire activity and the potential impacts of such a relationship under a changing climate. This project has been supported for a number of years by the CFS Fire Research and Climate Change networks and more recently by the Canadian Climate Change Action Fund. The work to date has involved the development of comprehensive historical databases of fire activity and fire weather for estimation of the current state of the fire regime and for evaluation of historical trends. General circulation models and regional climate models are also being used extensively in conjunction with the Canadian Forest Fire Danger Rating System for the development of potential scenarios of forest fire severity. The goal of this work is to provide the best possible estimates of both future levels of fire activity and area burned within the Canadian forest.

Future Direction

Past and current research has studied the impact of climate change on fire activity and forms a foundation for a discussion of the next steps in fire and climate change research. An overview of the key linkages between climate/weather and fire activity includes the role of meteorological variables, upper air patterns, and global circulation patterns (e.g., El Niño–southern oscillation, Pacific decadal oscillation) on fire activity. Future research should endeavor to describe the future fire regime, addressing fire frequency, intensity, size, season, severity, and type. This should allow us to estimate the impact on the landscape of a fire regime altered by climate change and consider options for adaptation and possibly mitigation. Such research would allow us to better define the key drivers of fire activity, including climate/weather, vegetation, ignition agents, and humans. Additionally, fire research cannot be done in isolation; we need to integrate efforts with research on other disturbances such as insects, disease, windthrow, and human activities. Humans have played a key role in fire through the ages and continue to influence fire activity in many ways, through fire management, vegetation fragmentation, other land-use issues, and ignitions.

Past and current research on fire and climate change has been conducted at local, regional, and continental scales. There is now a need to address fire and climate change at the global scale. This should be done in an integrated fashion so that feedbacks, nonlinearities, and interactions can be identified. Fire is an integral part of many ecosystems and human societies, and directed research would identify areas that are vulnerable to fire.

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