How “green” is your tree?

Written by Julianne Pickard

Christmas trees have become a common Christmas tradition in households across the globe. Since the 16^th century, people have been bringing nature into their homes to symbolise the start of the festive period. Today, many visit Christmas farms and choose their tree as an annual event, whilst others save time by bringing out an artificial version. Whatever the motive to go natural or artificial, the ‘carbon footprint’ aspect perhaps should be considered, and it seems that real Christmas trees may be greener than their plastic counterparts in more ways than one.

As you may expect, planting and growing Christmas trees have several environmental benefits before they even enter your home. The cultivation process creates a sink for carbon and nitrogen as these elements are taken up by the trees from the soil and air. This benefits the planet in a manner not dissimilar to wild forests- by reducing eutrophication and absorbing carbon dioxide (CO₂) (Binder et al. 2010).

Wildlife may also benefit from the Christmas tree industry in some areas, as plantations provide better habitats for many species than cultivated agricultural land. Studies in Europe have found increases in species richness and abundance of bird and insect life in areas where Christmas tree plantations are grown in areas with impoverished grasslands (Gailly et al. 2017, Hagge et al. 2019), and may provide important breeding refuges for declining farmland birds such as the common linnet and yellowhammer (Kämpfer et al. 2022).

The end-of-life process for Christmas trees can also have a positive impact on the environment since they are biodegradable and can be recycled. They can be disposed of in several ways, one of which involves breaking down the wood into woodchip and mulch for gardens. More recently, organisations such as the Ribble Rivers Trust have been using old Christmas trees to reinforce riverbanks through a conservation technique referred to as brash bundling. This method uses natural materials such as Christmas trees to prevent erosion and, over time, rebuilds the banks by trapping sediment from the river. Eventually, as the trees decompose, nutrients are restored, allowing vegetation to grow and adding structure to the riverbanks.

However, despite the discussed benefits of natural Christmas trees, there are several processes during their life which negatively affect the environment. When trees are disposed of, the CO₂ which was taken up during growth is released into the atmosphere and the amount released is dependent on the disposal procedure. If the tree is landfilled, the carbon footprint across its lifetime is -3.13kg CO₂, having a positive impact on the planet’s CO₂ levels. Nevertheless, many trees are incinerated, resulting in a carbon footprint equivalent to 5.12kg CO₂ (Binder et al. 2010).

These drawbacks, however, are put into perspective when compared to artificial trees. These are mostly manufactured in China (20% of the US artificial tree market) and on average contribute a carbon footprint of 18.6kg CO₂ across the tree’s lifetime. Most of this is due to the manufacturing process, with transportation being the second largest contributor. However, the longer an artificial tree is reused, the lower the environmental impact; if an artificial tree is reused for more than 4 years, there is a lower resulting carbon footprint than would occur from purchasing a natural tree every year for the same period. Moreover, natural trees only have a lower effect on global warming than artificial trees if they are disposed through landfill or recyclable processes showing how incinerating natural trees outweighs the carbon footprint gains from selecting a natural tree over artificial (Binder et al. 2010).

It is clear from these studies that, whilst there are benefits to the environment and wildlife by selecting a natural tree, the method of disposal is a significant factor in how green your tree actually is. Fortunately, there are a range of methods to dispose of trees in an efficient and environmentally friendly way. Several organisations collect used trees from your home to be recycled in return for a small donation. These can be found via this link and filtered by UK location. Alternatively, recycling points can be found on this site to drop off your tree or garden shredders can be rented online to create mulch for use in the garden. As a future green alternative, trees can be rented via sites such the one linked. The tree is collected from a local company and kept in your home over Christmas before returning to be replanted for the following year. The trees must be watered and kept away from direct heat whilst in your care and are nourished and trimmed throughout the rest of year. This offers a sustainable alternative to buying a tree and removes the carbon footprint and waste that comes with the disposal process.

Yet, regardless of the discussed environmental consequences of partaking in this festive tradition, all scenarios, whether artificial or natural, contribute to less than 0.1% of a person’s average annual carbon footprint. So, however you choose to spend your Christmas, remember that the overall impact of having any Christmas tree is very small compared to regular activities and does not significantly damage the environment (Binder et al. 2010).

All photos taken by Julianne Pickard in 2023.

References:

Gailly, R., Paquet, J.Y., Titeux, N., Claessens, H. and Dufrêne, M., 2017. Effects of the conversion of intensive grasslands into Christmas tree plantations on bird assemblages. Agriculture, Ecosystems & Environment, 247, pp.91-97.

Hagge, J., Seibold, S. and Gruppe, A., 2019. Beetle biodiversity in anthropogenic landscapes with a focus on spruce plantations, Christmas tree plantations and maize fields. Journal of Insect Conservation, 23(3), pp.565-572.

Kämpfer, S., Löffler, F., Brüggeshemke, J. and Fartmann, T., 2022. Untangling the role of a novel agroecosystem as a habitat for declining farmland birds. Annals of Applied Biology, 181(3), pp.367-378.