Welsh information

Love a tree to celebrate World Environment Day

By Sara Venn


World Environment Day is held on the 5th June each year, and this year’s theme is air pollution.

As we move into urban conurbations, populating our cities with not just ourselves, but with increased transport needs, industry and waste, the pressure on our air quality becomes higher and higher, and that effects not just our health but the health of the entire ecosystem within which we live. Our children are breathing air filled with diesel particulates, dust and fumes and there is increasing evidence that childhood respiratory illness is increasing along with allergies, many of which can be put down to poor air quality. Across the globe we see smog in many countries, fortunately something we no longer see in the UK as we don’t rely on burning coal in our homes and factories. Much of the world, however, is still reliant on these forms of energy and that air is circulating our globe and not helping the health of the planet’s many populations or the flora on which we all rely.

At Incredible Edible we are always looking for the local solutions to these global issues so we would like to look at how, as groups, we can support better air quality. We can walk or use public transport rather than relying on cars for journeys and we can ask others to do the same, but what can we do, on a practical level to support air quality at the same time as we are supporting our community with food and creating those gardens? And, of course, the answer is to plant trees!

In any edible landscape the importance of trees should never be forgotten but as well as providing a harvest they mitigate for poor air quality in the following ways…

Trees reduce the temperature through their transpiration and the canopy of a tree can affect air temperature, reduce wind speed and absorb radiation. So in summer in a hot and sticky city trees lower the temperature and support city cooling, whilst providing shade. Reduced temperatures as a result of planting trees is believed to improve air quality because emissions of many pollutants are temperature dependent. Trees also remove gaseous pollution either via uptake on the leaf stomata or the plant surface. Trees can also support cooling in buildings if they are planted close to them.

In our towns and cities we are all aware of trees in particular places that are obviously quite elderly and therefore also supporting populations we share our planet with. The reality of many urban and street trees, however, is an average life of 15 years which for most trees is not even beginning to reach full maturity.  So our other suggestion for World Environment Day is be aware of the giants you have in your area, and the importance of them for air quality for all the planets populations. If you don’t want to see them risk felling, put Tree Preservation Orders on them and make them an important part of your community. It might sound quite bizarre but in the knowledge that 50% of all the air we breathe relies on these gentle giants, it’s worth talking with your community about how you can support and treasure these vital lungs in our towns and cities.

Has your Incredible Edible group planted trees?  Contact us to let us know your story and we’ll share it to inspire others.  To find your nearest Incredible Edible group then search on our map, or sign up to the website to access our Getting going guide to start a new group on a street near you.