Trees and Climate Change

Our planet’s climate is changing. With climate change, extreme heat events are on the rise. According to a recent NASA study, Earth’s global average surface temperature in 2020 is tied with 2016 as the warmest year on record.

Climate change means more unusual and extreme weather. In 2019, for example, Environment Canada reported temperatures in Winnipeg and throughout parts of southern Manitoba ranged from -33 C to -40 C, but wind chills made it feel like -52 C – colder than parts of Siberia. Consider, though, that in 2020, triple-digit heat invaded Siberia, one of the planet’s coldest places.

Climate change is not something that may happen somewhere else in the future. Climate change is happening today, and it is happening right where we live.

To encourage urban nature by improving biodiversity, cities around the world are acting now to implement plans to plant millions of trees. Planting trees alone cannot stop climate change. Urban reforestation, though, is part of a natural solution to alleviate the effects of climate change.

The United Nations State of the Climate report, December 3, 2020, states that it is time to make peace with nature and time to “flick the green switch”. By planting trees, we are helping to build a more resilient future.

Important reasons to plant more trees in cities:

  • Tree canopies intercept rainfall and slow the flow of water when extreme rain events occur. This action helps to reduce the risk and severity of flooding. Trees are an essential part of stormwater management. Their large root systems intercept pollutants (for example, nitrogen and phosphorus) that can contaminate our water. Tree roots also help to anchor the soil and prevent erosion.
  • Trees provide measurable cooling effects by providing shade and reducing the urban heat island effect. In a warming climate, this is a significant benefit. Studies show that the right amount of tree cover can lower summer daytime temperatures by as much as 12 degrees Celsius (Science Daily). In winter, trees offer valuable protection to our home from strong winds, leading to reduced heating costs. Trees help to reduce carbon emissions when extreme temperatures occur in summer or winter by reducing the amount of energy usage needed for cooling or warming our homes and businesses. For example, the correct placement of trees around buildings can reduce the need for air conditioning by 30% and reduce winter heating bills by 20-50% (source: Food and Agriculture Organization of the United Nations).
  • In urban areas, trees have great potential to sequester carbon. According to the United Nations, a single mature tree can absorb up to 150 kg of carbon dioxide from the atmosphere and release healthy oxygen in exchange. It is estimated that one large tree can provide a day’s supply of oxygen for up to 4 people.
  • Cities are dusty. Trees filter dust by acting as excellent natural filters that remove particulate matter that contributes to air pollution.
  • Urban trees provide ecological benefits by increasing urban biodiversity and providing wildlife such as birds, butterflies, bees, and beneficial insects with valuable habitat, food, and shelter.
  • Trees foster a sense of well-being in our communities and are an essential component of healthy, walkable, livable spaces. Do you like to cycle? Do you enjoy running or walking your dog? Every activity is better on a street with trees.
  • Planting trees is an accessible, nature-based solution that helps us to envision a path forward to a more sustainable future – a future that benefits everyone.