Climate catastrophe is the greatest challenge we face. On a smaller scale, school pupils in city schools need cleaner air. Put these two challenges together and our best answer is the tree. Trees are probably our best defence against climate change. They capture carbon and remove other pollutants as they grow. They can also have a direct influence on pollution levels in the area they are planted. We need to plant far more of them.
In the UK we used to know this, but nowadays we have a low base to work from with only 47 trees per person, while neighbours France and Ireland have over three times this. In Europe, only the Netherlands appears to have fewer trees per person than us.
The UK Committee on Climate Change (CCC) recommended that 30,000 hectares of trees be planted every year but the government seems to have done little to address this. In 2018/19 the UK planted just 13,400 hectares of woodland, the majority of which was in Scotland.
Planting more trees should be a great and relatively quick fix but it does need to be done soon, really soon, to meet our climate change commitments and improve our health.
One suggestion in speeding this up is a series of public nudge programmes, like the “Plant a Tree in 73” campaign, that responded to a large depletion of trees caused by Dutch Elm disease and led to individuals planting hundreds of thousands of trees.
Engaging children in school projects is another way. It is often a great way to get information back into families and communities. A project starting with planting trees in school playgrounds could kick start a national debate and a larger tree planting programme. Given the air quality around many city schools, children in those schools would benefit from having pollutant removing trees around their school perimeter.
In the UK there are over thirty-two thousand schools including some four thousand nurseries and early-learning centres. If each of these planted 4 trees in their playground, that would be over 130,000 trees. Since typical tree densities range from 1000 to 2500 per hectare the 4 trees per school would be the equivalent of planting between 52 and 130 hectares of land. While this is a tiny project it will help also provide cleaner air, green space, greater biodiversity and nature projects for pupils.
I suggested just four trees per school as a minimum knowing that many city nurseries have only small play areas. However many secondary schools (especially those in the independent sector) have playing fields, playgrounds and car parks that could accommodate hundreds of trees around their borders and perimeters to provide carbon capture for the nation and clean air for pupils. On a sliding scale, with independent schools planting an average of 100 and state secondary schools planting 75 down to nurseries just planting 4 each, the contribution from schools could be in the region of eight hundred thousand trees providing the equivalent of between 320 and 800 hectares of trees. Not a bad contribution to the national target.
Director, Urban IQ Ltd.
 https://www.washingtonpost.com/graphics/world/tree-density/ and – Mapping tree density at a global scale. Nature, volume, 25, pp.201–205 (10 September 2015) https://doi.org/10.1038/nature14967