Forests are a vital part of the carbon cycle
Scientists agree and the evidence is clear (external link): the greenhouse gas (GHG) emissions we generate, primarily as a result of fossil fuels, are the leading cause of global warming (external link) and related volatile weather patterns. The negative impacts of climate change are a threat to the world’s forests, oceans, waterways and vital ecosystems.
Closely related to climate change is the earth’s carbon cycle. The carbon cycle refers to the continuous transfer of carbon from land and water to the atmosphere and living things. Forests are a vital part of this carbon cycle (external link), both storing and releasing it in a dynamic process of growth, decay and renewal.
Healthy forests can help cool the planet
The world’s forests help curb climate change and global warming by absorbing nearly a quarter of carbon emissions caused by human activity (PDF)—primarily the burning of fossil fuels and converting regions to farmland and other uses. By sucking up that carbon, forests reduce the amount of CO2 in the atmosphere and in turn decrease the impacts of climate change.
This means keeping forests healthy is a critical part of removing harmful emissions and cooling our planet. Trees absorb carbon as they grow and when made into wood products, continue to store that carbon over their lifetime. Natural regeneration and planting continue this cycle. Managing our forests sustainably, increasing our use of wood products over carbon-intensive materials and maximizing their reuse and recycling is a smart climate solution.
Forests as carbon sources and carbon sinks
Forests can act as both carbon sources and carbon sinks. When trees burn or decay, whether by old age, fire, insect attack or other disturbances, they release carbon into the atmosphere. Carbon is absorbed through photosynthesis, storing the carbon in the tree’s trunks, branches, roots, leaves and soil. A forest is a carbon source if it releases more carbon than it absorbs. It is a carbon sink if it absorbs more carbon from the atmosphere than it releases.
For the past century, B.C.’s managed forests have been a significant carbon sink, steadily adding carbon to that already stored. In more recent years, the impacts of climate change—forest fires and insect attacks—have led to a shift in the province’s carbon balance, with some forested regions becoming a source of carbon.
Photo credit: Michael Bednar
B.C.'s forestry sector could deliver significant carbon reductions
Building more with wood, when paired with region-specific forest management practices, can deliver significant emissions reductions for the province, according to the Pacific Institute for Climate Solutions. Under the best-case scenario modelled by the researchers, they concluded that B.C.’s forestry sector could potentially contribute to 35 per cent of the province’s 2050 emissions reduction target.
Photo credit: StructureCraft
Planting for future climate conditions and restoring the carbon balance
A dynamic approach to forest management is helping restore the carbon balance of B.C.’s forests while making them more resilient in the face of climate change. Using the latest science, B.C. researchers (external link)—in collaboration with the Canadian Forest Service, the University of British Columbia, and the United States Department of Agriculture’s Forest Service—are finding ways to minimize the impacts of wildfires and maximize the amount of CO2 absorbed by the province’s forests. By modelling a range of scenarios—such as different approaches to harvesting, silviculture and the use of bioenergy to replace fossil fuels—scientists are finding ways to adapt to warming temperatures.
One way the province is doing this is by researching growth rates and planting specific native tree species where future climate conditions can help them thrive. In fact, B.C.’s forests are growing one to three per cent faster per year on average according to a study from the Pacific Institute for Climate Solutions (external link).
For example, the black spruce—found in northern B.C.—is a native tree species that is growing twice as fast due to a warming climate. Another is western larch, which can now be planted north of its traditional range. With the right planning, climate change is and can continue to accelerate the regeneration of B.C.’s forests and even boost their carbon-absorbing benefits.
Photo credit: Jonathan Taggart
How wood construction can help fight climate change
Sustainably-sourced wood products help reduce the impacts of climate change. Their carbon-locking capability makes them an eco-friendlier choice when compared with non-renewable materials with high emissions such as steel or concrete. It is one of the few structural building materials we can grow using the sun while absorbing harmful CO2 emissions from our atmosphere. Cement, on the other hand, is the source of about eight per cent of the world’s carbon dioxide (CO2) emissions. Constructing more and taller structures with wood, and reducing our use of high-emission materials, such as steel and concrete, is a practical way to reduce the embodied carbon of our buildings.
Askew’s Uptown Supermarket | Photo credit: Derek Lepper Photography
Carbon Calculator
by Canadian Wood Council
Use the Carbon Calculator by the Canadian Wood Council to quantify the benefits of building with wood. Specific wood product and building information is put into the Calculator and the tool provides estimates of carbon storage in the building and emissions avoided as a result of using less carbon-intensive materials. This includes how much time it takes Canadian and US forests to grow that volume of wood along with the associated carbon benefits—both the amount of carbon stored and the amount of greenhouse gas emissions avoided.
Calculating environmental impacts of different building materials
Life cycle assessment (LCA) is the best method for examining the embodied carbon of building materials because it considers the greenhouse gas emissions associated with their production, transportation, construction, use and eventual disposal. National guidelines for whole-building life cycle assessment provide comprehensive instruction for the practice of life cycle assessment applied to buildings in Canada.
Various organizations have created online tools—embodied carbon in construction calculators—that take the whole lifecycle of products into account. Examples include Athena Sustainable Materials Institute’s Impact Estimator, Carbon Leadership Forum’s EC3 Tool, Building Transparency Tally and Bionova’s One Click LCA. Using these tools, building professionals can estimate the carbon footprints of their projects by plugging in the type and quantity of materials to test different options.
Zero-carbon buildings and the role of wood
While net-zero buildings that use less energy to operate than they generate are a good start, they don’t go far enough to reverse the accelerating effects of climate change. To meet global targets, and stop the world’s average temperature from rising, estimates show that all buildings will need to be net-zero-carbon by 2050 (external link). And science is showing that is possible to construct zero-carbon buildings—even make them a carbon sink (external link)—by using renewable materials such as wood.
The choice of products and systems used to construct, renovate and operate buildings has a significant effect on achieving zero-carbon building targets. Wood products are responsible for lower air and water pollution and have less embodied carbon than other commonly used building materials. Factory-built, precisely-manufactured timber construction makes better use of resources and reduces the number of deliveries to a building site, in turn decreasing overall vehicle emissions. Scraps leftover can be repurposed or recycled as bioenergy. These benefits, along with wood’s ability to serve as a carbon sink, make timber buildings a compelling choice to help achieve zero-carbon construction and design.
