Climate change is one of the defining challenges of our time. In response, protecting forests and preserving natural habitats is essential. In that same spirit, planting trees is a simple yet powerful action that everyone can take.

However, for this action to be truly effective, we must avoid planting just any tree, anywhere, or without proper planning.

Why Can Trees Help Fight Climate Change?

What Trees Do for Us

Trees provide a wide range of ecosystem services that benefit both the environment and the climate.

CO₂ Absorption

CO₂ is one of the main greenhouse gases responsible for global warming. Through photosynthesis, trees absorb large amounts of CO₂ from the atmosphere.

In doing so, they help reduce the impact of emissions generated by human activities—a concept we’ll explore further below.

Temperature Regulation

Through their canopy, trees block solar radiation and create shade. They also release moisture through transpiration, helping cool the surrounding air.

This makes them essential in reducing urban heat island effects.

Improved Air Quality

Trees act as natural air filters. They capture dust, reduce wind, and help trap certain pollutants and heavy metals.

Improved Water Quality

Their root systems stabilize soils and filter contaminants, preventing sediments from reaching waterways.

By absorbing rainwater, trees also reduce runoff and help recharge groundwater.

Biodiversity

Trees are key pillars of biodiversity, providing habitat, food, and shelter for a wide range of plant and animal species.

Understanding CO₂ Sequestration by Trees

Trees act as natural “sugar factories” through a cellular process known as photosynthesis.

Using sunlight, water, and CO₂, they produce sugars and release oxygen. These sugars (glucose) are carbon-based compounds.

Illustration of photosynthesis—plants absorb water through their roots and carbon dioxide through their leaves, then convert them into oxygen and sugars (C₆H₁₂O₆).

This is where the true climate value of trees becomes clear. A healthy, actively growing tree removes CO₂ from the atmosphere and stores it in its trunk, branches, roots, and surrounding soil.

Carbon is stored within the tree until it dies. As wood decomposes, carbon is gradually released back into the atmosphere through natural processes.

The strength of forests lies in their renewal: young trees replace older ones. At the ecosystem level, more carbon is captured than released.

This highlights the importance of protecting forests and planting the right trees in the right place. The healthier and longer a tree lives, the greater its contribution to carbon sequestration.

Which tree species are best suited to help fight climate change?

Start by consulting your municipality. Many cities in Quebec provide recommended species lists and may even offer planting incentives.

Trees Adapted to Their Environment

We also recommend consulting this guide to choosing the right tree. A well-adapted tree will grow better, live longer, and deliver greater environmental benefits.

Additional criteria can help maximize impact:

Fast-Growing Trees

Fast-growing trees with large canopies capture more carbon over time. Poplars and willows are excellent examples.

Long-Lived Trees

Long-lived species store carbon over extended periods. Oaks are a strong example.

Resilient Trees

Choosing resilient species ensures long-term stability. Important traits include:

• tolerance to summer heat and drought;
• resistance to strong winds and ice storms;
• tolerance to freeze-thaw cycles and extreme cold;
• tolerance to flooding.

Examples of Long-Lived and Resilient Native Trees

Several native Eastern Canada species are known for their longevity and resilience:

1. White Spruce (Picea glauca): Highly adapted to cold climates and can live up to 300 years.
2. Eastern White Pine (Pinus strobus): One of the tallest and longest-living trees in eastern North America, reaching over 400 years.
3. Eastern White Cedar (Thuja occidentalis): Can live up to 800 years.
4. Red Oak (Quercus rubra): A strong, long-lived tree that can reach 500 years.
5. Yellow Birch (Betula alleghaniensis): A long-lived species with strong ecological value.

For urban environments, consider:

1. Honeylocust (Gleditsia triacanthos): Fast-growing and adaptable.
2. Blue Beech (Carpinus caroliniana): A resilient and versatile species.

What Is the Best Tree Size to Plant?

Trees are available in several formats:

• Large-caliper trees (ball and burlap);
• Container-grown trees;
• Small-format or forestry seedlings.

In most cases, small-format trees are recommended.

Advantages of Small Trees

• Faster recovery from transplant stress;
• Quicker establishment and stronger early growth;
• Higher long-term carbon capture potential;
• More affordable;
• Easier to transport and plant.

Inspiring Tree Planting Initiatives in Quebec

Preserving natural habitats is essential to maintain biodiversity and ecosystem services.

In urban areas, tree planting plays a key role in improving air quality, reducing heat islands, and supporting wildlife.

Several Quebec cities have launched ambitious planting programs, including Montreal’s goal of planting 500,000 trees by 2030 and Quebec City’s 130,000-tree initiative.

Every tree planted contributes to healthier, more resilient ecosystems.

“The best time to plant a tree was 20 years ago. The second best time is now.”

– Chinese proverb