Canada's forests in a changing climate

Photo of a forest fire

The climate is changing and so are Canada’s forests. Increased numbers of large fires, greater drought frequency and intensity, shifting patterns of disease and invasive insect outbreaks: all of these trends over the last five decades are impacting Canada’s forests and have even resulted at times in loss of jobs and homes in some communities.

How the climate will continue changing is difficult to predict. But because Canada is a northern country, the changes are expected to be greater than the global average. How Canada’s forests will respond is also hard to know. However, scientists and other researchers are working to find answers that will reduce these uncertainties.

With the likelihood of new climate conditions, forests are expected to evolve, and in some areas become quite different from what they are now. Species composition, average age, geographic range and growth rates are all likely to change over the coming decades. This makes adaptation by the forest sector – such as planting drought-tolerant species – more important than ever.

If global efforts to address climate change are successful in limiting the world’s increase in temperature to 2°C, the increase in Canada is still forecast to average 4°C by 2100.

At the same time as they are affected by climate change, forests can also be part of mitigating (reducing) it. Trees absorb carbon dioxide (CO2) from the atmosphere and store it in their trunks, roots, branches and leaves. Increasing the area and growth of forests therefore reduces the amounts of greenhouse gases (GHG) in the atmosphere, helping to slow temperature rise. Using wood products and bioenergy also helps lessen the need for products made with processes that result in high GHG emissions and reduces the use of fossil fuels.

What effect is climate change having on Canada’s forests?

Canada’s scientists have long been studying how changing climate conditions are affecting the country’s forests. Among the most notable impacts observed:

  • Milder, drier climatic conditions over the past 50 years are thought to be a major reason for longer fire seasons and the increase in the number of severe forest fires and the size of areas burned.
  • In the 2000s, a series of warmer-than-usual winters enabled the mountain pine beetle to flourish and spread across much of central British Columbia. The outbreak killed more than 750 million cubic metres of mature lodgepole pine – a loss of more than 10 years’ worth of the province’s annual harvest. Researchers report that the beetle, now in north-central Alberta, the Northwest Territories and Saskatchewan (well beyond its natural historical range), may continue spreading east in the coming decades. It has already moved into new tree host species.
  • The current spruce budworm outbreak in the Mackenzie River delta in the Northwest Territories is taking place at the highest latitude ever recorded for such an infestation.
  • The increase in the rate of premature death of healthy trees in many forest types over the past few decades is likely the result of drought-related or other climate-triggered outbreaks of insects in weakened forests. Drought conditions have also contributed to the death or stunted growth of trees in several parts of Canada, including white spruce in Yukon (from spruce bark beetle infestation) and aspen in Alberta, Saskatchewan and Ontario.
Photo of regrowth after a forest fire

Science points to the changes in the world’s climate being the result of greater GHG emissions, including CO2, from human activities such as heavy reliance on fossil fuels, industrial production processes and global deforestation.

How forests could look in the future

Research on the biological, economic and social implications of climate change for Canada’s forests and forest industry is constantly improving our understanding of what the potential changes might be and how they could affect forest habitat and biodiversity, timber supply and communities.

Most areas in Canada, for example, are expected to experience at least a twofold increase in annual area burned by forest fires and a 1.5-fold increase in the number of large fires by the end of the 21st century. This means that the average age of the country’s forests is likely to decline in some areas, with increases in the number of young trees regenerating in burned-out areas.

Forest growth rates and the distribution of species may change gradually, too. Climate conditions have already shifted, affecting the distribution of certain tree species in Canada. The rate of climate change is projected to be 10 to 100 times faster than the ability of tree species to migrate. This means that some tree species will benefit (for example, growing faster or spreading more widely), while others will become increasingly stressed, potentially dying out over time.

Given Canada’s vast and generally remote forests, measuring, monitoring and tracking the changes in them is challenging. The National Forest Inventory (NFI) is an important tool for tracking or monitoring current and projected changes in the forest. It will also become increasingly important as a means of providing early warning of climate change impacts and tracking ongoing change in our forests.

Such changes pose broader ecological consequences as well, affecting vegetation and wildlife, which would need to adapt or migrate under changing climate and forest habitat conditions.

Forest sector adaptation to climate change is needed

Adapting to climate change means adjusting decisions and activities to take into account observed or expected changes in climate. In the forest sector, that means integrating climate change knowledge into sustainable forest management planning and practices to help maintain both ecosystem integrity and the flow of social, economic and environmental benefits. Planting a greater diversity of tree species in a forest, for example, is one way of reducing the forest’s vulnerability to future insect infestation or fire risks.

Adaptation efforts help forest ecosystems, the industry and forest-dependent communities across Canada reduce their vulnerability to the negative effects of climate change.

Adaptation measures are specific to a region and forest type and therefore vary widely. What best suits the local environmental and socio-economic needs in a region on the east coast might not offer the best solution on the west coast or in the northern boreal forest. The infographic The climate is changing and so are Canada’s forests shows examples of adaptation actions that can be taken.

Adaptation will also be important to industry and communities as they adjust to the changing forests they rely on. Harvest levels, for instance, may need to be reduced as more-frequent natural disturbances reduce the available timber supply. Forest companies will need to increase their efforts to find innovative ways to use more dead or low-quality wood salvaged from burned areas or areas invaded by insects or disease. Communities located in forested areas are already being encouraged to be “fire smart” by clearing trees and general forest brush (living and dead) from areas between buildings and forest.

Since 2008, the Canadian Council of Forest Ministers (CCFM) has focused on what adaptation means for sustainable forest management. A series of the CCFM’s reports offers forest managers guidance in assessing the vulnerabilities, risks and opportunities associated with climate change. Many forestry organizations are using the reports to inform policies and practices.

Forest Change, a component of the Government of Canada’s adaptation program, was also launched in 2011 to support the forest sector in adapting to climate change. The program provides science-based information and analysis on past trends and future projections of climate change impacts on the forest and the forest sector. And its tools are helping forest managers and others in the sector develop and implement adaptation plans and take action to adjust to the future climate.

Infographic

Infographic: The role of forests in the carbon cycle
The role of forests in the carbon cycle illustrated in an infographic composed of elements such as soil carbon storage, carbon emissions, carbon removals and flow of carbon from one pool to another. Diagram shows a forest fire, forest growing, decomposition, deforestation, afforestation, harvesting, burning and landfills (from wood harvesting to the mill: wood products, bioenergy and landfills).

Using Canada's forests to help mitigate climate change

At the climate change conference in Paris in December 2015, Canada joined the international community in aiming to achieve near-zero GHG emissions by 2050. Canada has committed to a 30% reduction in its emissions (below 2005 levels) by 2030. Further emission reductions will be needed after that in order to meet the international ambition of keeping the global temperature increase to below 2°C.

Given the current and projected impacts of climate change on Canada’s forests, it may seem counterintuitive to think that forests can also be part of the climate change solution. However, the carbon-storing capacity of forests, together with the ability of wood products to replace fossil-fuel-intensive products, can contribute to keeping CO2 out of the atmosphere. For more information, see the carbon emissions and removals indicator.

The ways in which forests are managed (tended, harvested and regenerated) and harvested wood is used can therefore make important contributions to Canada’s efforts to meet its climate change commitments. Among the mitigation actions being considered by various jurisdictions are the following:

  • Increase the overall forest area – Landowners could plant new forests on lands not currently part of the managed forest.
  • Use sustainable forest management practices that reduce GHG emissions and store carbon – Forest managers could limit on-site burning of harvest waste (such as stumps, bark and branches), using it for bioenergy instead; make more complete use of the material harvested; speed up reforestation after natural disturbances; and increase growth rates in appropriate locations through intensive management.
  • Use more wood in construction – Builders could use more wood from sustainably managed forests in non-traditional construction applications in place of other materials whose manufacture, use and disposal involve higher amounts of GHG emissions. The practicality and environmental benefits of using wood in construction are already being demonstrated in ever larger and taller wood buildings. For more information, read "Taking wood buildings to new heights".
  • Use more wood waste for energy and other bioproducts – Industry and individuals could increase the use of waste wood for energy to replace fossil fuels or use bioproducts that replace similar products made from fossil fuels. For more information, read "5 reasons why wood is one of Canada’s most valuable resources".

Some of the emission-reducing benefits from these activities would be immediate. Other benefits would take more time to achieve. For this reason, the sooner mitigation actions are undertaken, the more they will help Canada meet its GHG emission reduction target for 2030 and its longer-term move to a low-carbon economy.

The federal government, provinces and territories are working together to develop a pan-Canadian framework for climate change. Launched by the Prime Minister and Premiers in March 2016, the framework aims to develop and implement a plan for how Canada can achieve its 2030 climate change target.

Looking ahead to minimizing future climate change impacts

While there is no certainty about future climate or forest conditions, the impacts of current climate change on forests is evident in more frequent fires, insect and disease outbreaks, and drought. Canada’s scientists are working with others around the world to equip decision-makers at all levels with knowledge and tools to better anticipate the climate challenges ahead.

An example is Canada’s carbon monitoring and reporting system. It tracks how emissions are changing and is a useful tool for devising carbon mitigation strategies. Other tools, such as assisted migration and risk assessment guidelines, have also been developed. Forest managers are already using these to adjust their thinking and their management practices to support the long-term sustainability of Canada’s forests. New strategies, tools and practices will continue to emerge as research adds to our knowledge of the complex relationship between forests and climate.

As a biological resource, forests are on the front line in experiencing the effects of the ongoing changes. And as a renewable resource made of carbon, they are part of the climate change solution. For both reasons, helping our forests adapt is critical for maintaining their health and for ensuring that mitigation strategies are successful.