Planting trees, or reforestation, is the most evident solution for combatting deforestation. Currently, it is one of the most popular methods being used by governments and environmentalists in their fight against climate change. The UK government has ‘planted millions of trees over the last decade and has pledged another million between 2020 and 2024.’ᶦ Notably, even the Daily Mail, not known for climate-change activism have encouraged readers to plant trees!
However, reforestation is not as critical as preserving current forests. The best way to break this down is by closely analysing young trees versus old trees:
Young trees have good potential to slow down climate change, but according to the UK’s Royal Society, it takes planted trees at least 10 years to reach their maximum carbon sequestration rate – the point at which they can absorb the most tonnes of carbon from the atmosphere every year.ᶦᶦ Additionally, they are:
Smaller – this means they don’t hold as much carbon as older trees
Weaker – increases their risk of dying from natural disasters
Young – cannot support biodiversity, endangered species or wildlife habitats
Not to mention, they need nurturing. However, most tree planting initiatives don’t consider aftercare following planting, so many trees may not grow, survive, or even reach maturity.
In comparison, older trees are:
Tall and grown – this means they can hold a larger amount of carbon
Strong – can withstand natural disasters and have developed a network of nutrients by intertwining their roots underground with trees around them to lend support to weaker trees
Part of a natural ecosystem
Further, a 2018 study on the global importance of large-diameter trees found that, on average, 50% of the live tree biomass carbon in all types of forests globally is stored in the largest 1% of trees.ᶦᶦᶦ Thus, when these old and large trees are cut down, the carbon trapped within enters the air. Deforestation contributes four billion tonnes of CO2 emissions to the global total of 41 billion tonnes of CO2.ᶦᵛ So, if we stopped cutting trees, we would cut annual emissions by approximately 10%.
To conclude, William Moomaw, a lead author for five reports of the Intergovernmental Panel on Climate Change (IPCC) stated ‘tree planting is a great thing to do, but [it] will not make much of a difference in the next two or three decades because little trees just don’t store much carbon. Letting existing natural forests grow is essential to any climate goal we have.’ᵛ A clear priority moving forward should be to increase the quantity of protected forests worldwide so that the largest trees storing the most carbon can be given sanctuary against being cut down for trade.
ᶦ Marshall M, ‘Planting trees doesn’t always help with climate change’ (26th May 2020, BBC News) < https://www.bbc.com/future/article/20200521-planting-trees-doesnt-always-help-with-climate-change>
ᶦᶦ The Royal Society, ‘Greenhouse Gas Removal.’ (September 2018) < https://royalsociety.org/-/media/policy/projects/greenhouse-gas-removal/royal-society-greenhouse-gas-removal-report-2018.pdf>
ᶦᶦᶦ Lutz, J. A., Furniss, T. J., Johnson, D. J., Davies, S. J., Allen, D., Alonso, A., et al. (2018). Global importance of large-diameter trees. Glob. Ecol. Biogeogr. 27, pg. 849–864.
ᶦᵛ Le Page M, ‘Bad news: Carbon emissions have suddenly started rising again’ (13th November 2017, NewScientist) <https://www.newscientist.com/article/2152929-bad-news-carbon-emissions-have-suddenly-started-rising-again/>
ᵛ Moomaw WR, ‘Intact Forests in the United States: Proforestation Mitigates Climate Change and Serves the Greatest Good’ (11th June 2019, Frontiers) <https://www.frontiersin.org/articles/10.3389/ffgc.2019.00027/full?te=1&nl=climate-fwd:&emc=edit_clim_20200328>