Trees and Climate Change

If we were to search for a positive to come out of the past year, it was the opportunity for society to take pause, and consider life beyond the pandemic. A new-found appreciation for clean air and green spaces has kick-started a wave of “build back better and greener” sentiments.

As a result of this shift, tomorrow marks the inaugural World Rewilding Day – celebrating the return of nature and exploring solutions to conserve existing wild spaces so that birds, bees, bugs and small wildlife can be restored.

Throughout 2020, countless scientific papers told us that planting billions of trees across the world is one of the biggest and cheapest ways of taking CO2 out of the atmosphere to tackle the climate crisis. The report divided opinion, with many commentators arguing that planting trees is not enough to tackle climate change. They’re not wrong; tree planting is just one part of the solution to tackling the climate crisis. But we shouldn’t dismiss the significant contribution that tree planting can offer when it is considerately/carefully implemented alongside other technologies and innovations to address climate change impacts.

Last year, the Committee on Climate Change released a report entitled ‘Land use: Policies for a Net Zero UK’. One of its key findings was that the UK should increase its forestry cover from 13% to at least 17% by 2025by planting around 30,000 hectares of broadleaf and conifer woodland each year. It is thought that this would directly stimulate emissions reductions across the UK and help the Government deliver its net zero greenhouse gas emissions target by 2050.

Trees – all plants, in fact – use the energy of sunlight, and through photosynthesis, they take carbon dioxide (CO2) from the air and water from the ground. In the process of converting it into wood they release oxygen into the air. In addition to the CO2 that trees capture, they also help soil capture significant amounts of carbon. It is estimated that a single mature tree can absorb 48lbs of carbon a year and makes enough clean oxygen for 4 people to breathe fresh air.

Besides absorbing carbon, trees play a number of other vitally important roles in addressing climate change. Trees protect coastal communities from severe flooding and storms, by slowing the water’s strength as it surges on land, and by absorbing excess water in the soil and releasing it as water vapour into the air. The shade that trees provide is also important in helping soil retain moisture rather than drying out, and so supports fertile agriculture. More shade and less sun in urban areas also helps reduce energy consumption when it’s hot. Finally, trees are the anchors for plant and wildlife biodiversity – they contribute to healthy ecosystems and a single tree can be home to hundreds of species of insect, fungi, moss, mammals and plants.

A report published in Science found that there are in excess of 3 trillion trees already on earth. However, this latest research shows that the space available for trees is far greater than previously thought and would reduce the CO2 in the atmosphere by 25%. The new report showed not just how many trees can be grown, but where they could be planted and how much of an impact they would have on carbon emissions. Using the mapping software of the Google Earth engine, they were able to develop a predictive model to map the global potential for tree cover. They found that excluding trees, farmland and urban areas, the world could support an extra 0.9bn hectares (2.22bn acres) of tree cover.

This expanded tree cover not only sequesters carbon but is a great way to help beleaguered pollinator populations. With bees and other pollinators fast declining around the world, it is vital that societies look at innovate ways of safeguarding this vital part of the ecosystem. Here at Low Carbon we are particularly mindful of this and continue to collaborate with the Energy and Environment research team at Lancaster University, looking at ways in which renewable energy sites can actively ecosystem benefits through best practice, amongst other projects.

Given what we know about the potential for tree planting and the impact that it can have alongside other climate change mitigation techniques, in 2019 Low Carbon committed to offsetting our corporate travel carbon emission by planting trees. For Low Carbon, planting trees is complementary to what we do in renewables and biodiversity, it is measurable and has a positive environmental impact, and it enables us to create a long-lasting legacy. Low Carbon will continue to make regular donations to the Woodland Trust via their Woodland Carbon Scheme to help plant and maintain trees in the UK as part of its commitment to balancing profit and purpose. Watch this space to hear more updates on our tree planting journey.