Trees. We know they are important to help us tackle climate change, but how many of us really understand just how and why they are so great? As we celebrate National Tree Week it seems a good time to explore the super power of trees.

Trees are the biggest, heaviest and oldest things on planet Earth and yet most of us don't really notice them. These amazing things are crucial to life on Earth; they provide us with food and wood, they make our air clean and research has shown that they also make us happier!

Our sustainability expert Sarah Walkley takes a stroll through a forest of tree-mendous facts.

Trees help us breathe

A tree absorbs an average of 25kg of carbon dioxide a year and locks it up in its leaves or directs the carbon down through its root system into the ground. That’s the equivalent to the carbon dioxide emissions produced by a single car driving from London to Cambridge.

Let’s scale that up. There are an estimated 400bn trees in Europe, capable of absorbing almost 9% of the continent’s greenhouse gas emissions, or the emissions produced by all the private cars, motorbikes and vans on Europe’s roads.

Trees absorb carbon by photosynthesis and produce oxygen. 7 trees produce enough oxygen for an adult for a year.

Trees help keep us cool

When it rains, trees soak up water and store it in their roots and leaves, helping to reduce flooding and soil erosion. A large oak tree can absorb more than 400 litres of water in a day. That’s more than 8 baths full of water.

Later they release up to 95% of the water. A process known as transpiration. This helps to keep us cool.

Having lots of trees in cities can reduce the temperature by up to 8°C. That means that one tree could replace two energy-hungry air conditioning units.

Trees also filter water and remove pollutants. New York’s 9m residents drink water that has been cleaned by passing through nearby forests.

Where are the trees going?

So why are we chopping down trees at an alarming rate? In 2019, we lost a patch of rainforest the size of a football pitch every six seconds.

The loss of trees in tropical areas now causes more emissions than 85m cars, or the number of new vehicles sold worldwide in 2021. If tropical deforestation were a country, it would rank 3rd in the list of the world’s highest emitters behind China and the United States.

But while we have lost a large area of forest in the tropics over the past 40 years, we have covered an area more than 2 ½ times the size with new trees – mainly in the Northern hemisphere.

… but we can still plant more!

And it doesn’t need a lot of land to plant more trees. A tiny forest crams around 600 trees into a space the size of a tennis court. Squashed together, the trees grow up to 10 times faster than other trees and absorb up to 30 times more carbon dioxide. Schools up and down the UK are planting tiny forests. There are now over 150 of them in the country.

Want to learn more?

If your little eco heroes love getting outside amongst the trees, then be sure to check out our TREMENDOUS TREES themed eco-activity box. It’s packed with 6 hours of fun to keep your little eco heroes busy including a guide to exploring the great outdoors, learning about the seasons with a painting activity, baking spiced apple muffins, an Eco Hero card, collectable card and something extra for grown ups. Activities include learning how to measure trees, making a papier mâché globe, crafting with nature as well as planting a tree for tomorrow. Take a look here.

Sarah Walkley is a freelance writer and researcher on a mission to empower everyone to play their part in addressing climate change and nature loss.

She set up Purplefully to help organisations develop their sustainability strategy and communication.