Aug 20, 2019
‘Tree hugger’, rather than referring to someone who actually hugs trees, is usually a disparaging or unfavourable term for a person who cares deeply about the environment. However, we all know sticks and stones can break our bones but names will never hurt us. Well, loving trees will definitely not hurt us; in fact they may well help save us from some of the worst effects of climate breakdown. Meryl Batchelder suggests now is time that we all start to embrace trees.
Climate change should alter the way we think about trees
Put your hand up if you have appreciated a tree today. Any tree. It should be easy as there are approximately three trillion mature trees on Earth to choose from. I’m hoping I’m wrong but my guess is many of you won’t have thought of a tree at all. Maybe that is because trees were in existence for 370 million years before humans evolved so it is easy to overlook them.
We all know the basics; they have a trunk, branches and leaves – some are evergreen like holly and others are deciduous such as the common oak or sycamore which lose their foliage in winter. Below the ground, roots spread out anchoring the tree and extracting moisture and nutrients from the soil.
Trees can be climbed or used for shade for a picnic. Specific types of tree provide foods and spices such as apples, walnuts, maple syrup and cinnamon. If cut down trees can be used for fuel, as a building material, to make paper for the books you read or even as a Christmas tree. They are part of our everyday life but many people walk past the same tree every day without even noticing it or may struggle to name more than a few different species.
Increasingly trees have been appearing in news articles; from stories on the depressing destruction of parts of the Amazon rainforest to the joyous, record breaking, event in Ethiopia where 350 million trees were planted in just one day. In fact, these are probably just the start, trees are about to become hugely significant to all of us as they can help to mitigate climate change. Gone are the days when we can take trees for granted.
Trees are fascinating – ask any dendrologist. A single tree is a complex organism which supports a huge number of other living things and an entire forest provides habitats for countless interdependent species. On a global scale boreal forests are found towards the poles, tropical forests grow around the Equator and temperate forests at the middle latitudes.
On a smaller scale the parts of the tree can be fascinating; silver birch bark can be peeled into paper thin strips that can be used as kindling whereas Scots pine bark actually offers protection from fire. Try collecting a few green leaves and identify the different species then look at the underside of a leaf with a magnifying glass and see if you can find the almost microscopic stomata which allow for gas exchange. It is these stomata, and the green pigment in the leaves, that are key to helping us tackle climate change through their role in removing carbon dioxide from the air.
The problem with carbon dioxide
The current global heating of Earth has been proven to be caused by humans. The average global temperature is currently 1.2 degrees Celsius hotter than pre-industrial levels. Increasing carbon dioxide levels in the atmosphere are directly linked to the burning of fossil fuels. We have already started to see the effects of increasing temperatures with destabilised weather patterns around the world.
What is most concerning is that the release of carbon dioxide and other greenhouse gases through industry, agriculture and transportation has been increasing in recent years – this could lead to a 2 degrees Celsius temperature average rise by 2050 and even higher future rises unless we drastically reduce the amount of carbon dioxide in the atmosphere.
There may be technologies developed over the coming years that can mechanically or chemically reduce the amount of carbon dioxide in the air. But there are no guarantees these new technologies will work to scale and they could be incredibly expensive. So, let us think of a natural way to absorb, and lock in carbon from the atmosphere. You’ve guessed it, trees!
Gas exchange by plants
The reason the leaves of a tree are green is that each leaf is made of cells that contain chlorophyll in an organelle, or part of a cell, called a chloroplast. Chlorophyll produces the food needed by the tree so it can grow. During the photosynthesis reaction energy from sunlight enables plants to use carbon dioxide from the air which enters through the stomata with water drawn up through the roots to produce a sugar called glucose. The other product of this important reaction is oxygen (which is obviously crucial to humans too).
Trees reduce the amount of carbon dioxide in the atmosphere and store it in their cells even when the tree is chopped down. This is one reason houses should increasingly be made of wood as bricks and cement produce carbon dioxide when they are manufactured. In fact, if cement was a country it would be the third biggest emitter of carbon dioxide in the world after China and the USA. The benefits of wood don’t end there as planted trees can also reduce flooding; they slow down water runoff, allowing the water to percolate into the soil and they reduce the amount of valuable soil washed away.
Planting trees to combat climate change
In order to meet the net zero emissions target set by the UK Government, alongside the rapid reduction in the amount of fossil fuels that are burned, Britain needs a three-fold increase in woodland creation levels– simply put we need to plant 1.5 billion trees by 2050.
Even if every household with a garden in the UK planted two trees that would only amount to 45 million. The percentage of woodland cover in the UK needs to increase from 13 to 17%, a gigantic challenge but it would be worth it. Research by Crowther Labs estimates that a worldwide planting programme could remove 66% of all the emissions that have been pumped into the atmosphere by human activities. Planting billions of trees won’t solve all the problems – but it is the best solution that we currently have.
Woodlands can also help to promote biodiversity. The restoration of ecosystems that have been mismanaged by humans is called ‘rewilding’. The aim is to reinstate natural processes and, when appropriate, missing species then step back and allow nature to look after itself. Several rewilding experiments are taking root across the UK such as in Ennerdale in the Lake District where spruce are gradually being replaced by native broadleaves. New woodland can help to enhance biodiversity, store carbon, reduce flood risk and generate jobs.
Nurture existing trees
This has been a year of climate records being broken and Earth is giving us fair warning that existing trees also need love. Many species with limited range such as the iconic Joshua trees of the Mojave desert or the ancient bristlecone pines of upland California are threatened by increasing temperatures.
Longer periods without rain mean we are also losing woodland to wildfires. During record breaking temperatures in February wildfires tore through Ashdown Forest in Sussex, best known for inspiring the Hundred Acre Wood in the books about Winnie the Pooh. Over the summer swathes of the boreal forest in Siberia have been ablaze destroying ancient woodland and contributing to global heating in the process.
In Africa many of the immense baobab trees, which are locally considered to be the tree of life, are dying with the finger of guilt pointing at climate change. Closer to home, in the UK and Europe the ash tree, named Yggdrasil, is the Norse mythology tree of life but millions are dying from ash dieback disease. Losing existing trees to climate change or disease makes our tree planting efforts even more critical.
Maybe we could all select a favourite tree to appreciate. Mine is currently in my garden growing from a conker that my son planted when he was four years old. Over the years we have enjoyed watching it grow into a sapling and then into a young horse chestnut tree. My son is now 15 and 1.8m tall and earlier this year his tree overtook him in the height competition. He’ll stop growing soon but that tree, all being well, may reach the height of 40m and have a life span of 300 years which makes us humans seem more than a little insignificant.
A tree-hugging badge of honour
For successful climate action, in addition to reducing the amount of energy we use, eating less meat and wasting less food, we also need to protect our soil and plant trees. Autumn and winter are the perfect times for planting. Selecting and planting a family tree for Christmas would be much better than cutting one down.
My family has gone one step further and over the past five years we have planted around 1000 native woodland trees around our smallholding including oak, maple, rowan, birch, aspen, holly, Scots pine, hazel, hawthorn and willow. I think I’ve earned my tree-hugging, climate-saving, habitat-providing badge of honour and I will wear it with pride.
Taking learning further
- Write a story or poem about a tree or forest near you.
- Link trees to the SDGs as part of a project on habitats, plants or environmental interdependence. There are links to SDG2, SDG3, SDG11, SDG13, SDG15 and more.
- Read about the Ethiopian tree planting world record
- Change your internet search engine to Ecosia which plants trees in return for searching the web.
Start a rewilding project with school:
- Find the right species for you to plant
- Where can you plant trees
- Charities which may be able to assist a school planting scheme: