How trees (and you) can make our air cleaner

This Clean Air Day, there are simple steps we can all take to cut down on the air pollution we cause and use our voices to fight for a cleaner air future.

What is air pollution?

The WHO defines air pollution as “the contamination of the indoor or outdoor environment by any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere… Many of the drivers of air pollution (i.e. combustion of fossil fuels) are also sources of greenhouse gas emissions… WHO data show that almost all of the global population (99%) breathe air that exceeds WHO guideline limits and contains high levels of pollutants.”

The causes of air pollution

- Traffic emissions

- Power plants

- Industrial facilities

- Agricultural processes

- Domestic burning (including wood burning stoves)

How trees clean the air

Trees shade surfaces which reduces temperatures and decreases the risk of ground level ozone that can spike in urban areas during hot weather. They also counteract the warming effects buildings have on the environment (urban heat islands) through the cooling effect of evaporation of water from the soil and through leaves. They absorb carbon dioxide and emit oxygen through photosynthesis, and filter sulphur dioxide and nitrogen dioxide through their leaves, bark and roots, This improves the air quality in the micro-climate directly around them. Trees are particularly good at removing particulate matter (PM) which is produced by vehicles, factories and construction sites. They do this by dispersing the particles or trapping them in their leaves.

Trees are hugely important in the fight against both climate change and air pollution, but they can’t solve the problem entirely. Our actions have a cumulative effect, as the less pollution we produce will also result in better air quality.

How you can contribute to cleaner air and cut down emissions

-  Walking or cycling short journeys instead of driving

-  Switch your engine off when you are stationary

-  Join a car club

-  Avoid non-essential, polluting deliveries or choose a carrier that is carbon neutral

-  Open windows and use extractor fans when cooking or cleaning at home

-  Work from home if possible

-  Avoid using wood burning stoves or open fires

- Talk to someone about air pollution or share this article

Clean Air Day is a chance for us to wise up about air pollution, share information with our friends and colleagues and take action to make the air cleaner and healthier for everyone. Find out more here: or head to: