Tree Planting & How It Affects Global Warming

tree planting

This video explains how tree planting affects global warming

 

Throughout the end of 2019 and the beginning of 2020, Australia experienced what is referred to as its Black Summer. This was a season of intense bushfires that blighted the world. By March 2020, an estimated 19 million hectares of forested land had burned down, destroying at least one billion animals1 and affecting 80 per cent of all Australians.2 It was a stark reminder of how tree planting is directly related to our security and safety.

deforestation and forest fires

Australia’s bushfires

These Australian bushfires were the country’s most expensive natural disaster.3 They were also predicted. In August 2019, the Queensland Fire and Emergency Service warned that the bushfire season was likely to come early and be intense due to the heat and climate change. But these warnings were not taken as seriously as they should have been. Perhaps the world can learn something from this.4

old tree
Photo by Damir Mijailovic

How will planting a tree affect the environment?

Trees have an incredible impact on the environment on a global and regional level. They provide shelter for plant and animal species, they supply jobs to millions of people, they can be a source of recreation and tourism, they attract rainfall, and they protect our soil.5

The effect of trees’ leaves, branches and root ball

Plants and trees enrich the surrounding soil in several ways. The organic matter they drop is used as food by the microbes and bacteria below. The organic matter usually takes the form of leaves, branches and wood. This cycle enriches the soil and helps to absorb more carbon dioxide from the atmosphere.6 A tree’s roots also hold on to soil and water, preventing flooding and keeping the soil healthy.7

More good reasons to plant a tree

Trees can also affect rainfall. Tree leaves catch falling rain and allow that to evaporate easily – a process known as evapotranspiration. “Evapotranspiration is a very large component of rain generation – on average about 50% in summer across the globe, and 40% on an annual basis”, says David Ellison from the Institute for World Economics. Scientists think that eventually, once we know more about the relationship between trees and rain, we could strategically plant certain trees to increase rainfall in a region.8

International examples of tree planting efforts

In Australia’s case, it was already facing an extremely dry season exacerbated by climate change. That led to forests being incredibly dry and prone to fires, increasing the likelihood of severe fires.9

Many governments have begun to appreciate the benefits of tree planting to the regional ecosystem. In China, farmers were explicitly helped to plant more trees to help control soil erosion and make the land more fertile. That effort led to a significant improvement in the local environment and farmers’ incomes.10

tree planting
Photo by Trang Dinh Le

How can trees help to check global warming?

Trees don’t just affect the local environment, they are among the main checks on global warming. Trees stop our planet from overheating by turning carbon dioxide into oxygen through photosynthesis. They also absorb and store that carbon as organic matter by using it to build leaves, stems and trunks.11

Tree planting and carbon dioxide

Between 2001 and 2019, forests around the world absorbed around 15.6 billion metric tonnes of carbon dioxide from our atmosphere every year, according to NASA researchers. They also found that deforestation, fires and other disturbances released an average of 8.1 billion metric tonnes of carbon dioxide per year over the same time period.12

Tree planting and global warming mitigation

In other words, forests store the carbon dioxide that we release. Burning or cutting these forests down releases that stored carbon. If the world planted over one trillion trees, they could absorb up to 100 years worth of carbon emissions, a study in 2019 indicated. Scientists have said that trees have a “mind-blowing potential” to stop global warming.13

Tree planting is not the only solution

There is little doubt that planting trees is the best way that we currently have to remove carbon from the air. But scientists warn that they are not an alternative to drastically cutting our carbon emissions. Without trees, carbon dioxide levels in the atmosphere would be far higher, leading to runaway global warming.14

Tree planting and its potential detriment to global warming

It is also worth noting that forests may not always help with global warming. In some cases, forests may actually lead to an increase in carbon emissions. Some tree species can have a relatively high carbon and methane emissions. In other cases, forests may absorb more sunlight rather than repelling it, thus warming local regions.15

Nevertheless, Australia’s unprecedented fires were a reminder that trees are not just a crucial part of our lives, but that their health is directly related to our health. Therefore, we must protect them.

Sources

  1. Filkov, A.I., Ngo, T., Matthews, S., Telfer, S. and Penman, T.D. (2020). Impact of Australia’s catastrophic 2019/20 bushfire season on communities and environment. Retrospective analysis and current trends. Journal of Safety Science and Resilience, [online] 1(1), pp.44–56. Available at: https://www.sciencedirect.com/science/article/pii/S2666449620300098.
  2. Edwards, B., Herz, D., Biddle, N. and Makkai, T. (2020). Nearly 80% of Australians affected in some way by the bushfires, new survey shows. [online] The Conversation. Available at: https://theconversation.com/nearly-80-of-australians-affected-in-some-way-by-the-bushfires-new-survey-shows-131672.
  3. Read, P. and Denniss, R. (2020). With costs approaching $100 billion, the fires are Australia’s costliest natural disaster. [online] The Conversation. Available at: https://theconversation.com/with-costs-approaching-100-billion-the-fires-are-australias-costliest-natural-disaster-129433.
  4. www.abc.net.au. (2019). “Bushfires from Rockhampton to the border”: Long bushfire season ahead. [online] Available at: https://www.abc.net.au/news/2019-08-28/queensland-bushfire-season-starts-earlier-lasts-longer/11456576 [Accessed 21 Apr. 2021].
  5. wwf.panda.org. (2015). The Importance of Forests. [online] WWF. Available at: https://wwf.panda.org/discover/our_focus/forests_practice/importance_forests/.
  6. www.rhs.org.uk. (n.d.). Organic matter: how to use in the garden. [online] Available at: https://www.rhs.org.uk/advice/profile?pid=865.
  7. Worldagroforestry.org. (2021). 5.2 How trees improve soils. [online] Available at: http://apps.worldagroforestry.org/Units/Library/Books/Book%2006/html/5.2_how_tree_imp_soi.htm [Accessed 21 Apr. 2021].
  8. Evans, K. (2012). Make it rain: Planting forests could help drought-stricken regions – CIFOR Forests News. [online] CIFOR Forests News. Available at: https://forestsnews.cifor.org/10316/make-it-rain-planting-forests-to-help-drought-stricken-regions?fnl=en.
  9. www.ox.ac.uk. (2020). Australia’s bushfires “made 30% more likely by climate change” | University of Oxford. [online] Available at: https://www.ox.ac.uk/news/2020-03-12-australia-s-bushfires-made-30-more-likely-climate-change.
  10. World Bank. (2017). China: Afforestation Project in Shandong Improves Environment and Farmers’ Incomes. [online] Available at: https://www.worldbank.org/en/results/2017/07/26/china-afforestation-project-in-shandong-improves-environment-and-farmers-incomes.
  11. BBC (2019). What is photosynthesis? [online] BBC Bitesize. Available at: https://www.bbc.co.uk/bitesize/topics/zvrrd2p/articles/zn4sv9q.
  12. Bates, S. (2021). NASA Satellites Quantify Forests’ Impacts on Global Carbon Budget. [online] NASA. Available at: https://www.nasa.gov/feature/goddard/2021/nasa-satellites-help-quantify-forests-impacts-on-the-global-carbon-budget.
  13. Carrington, D. (2019). Tree planting “has mind-blowing potential” to tackle climate crisis. [online] the Guardian. Available at: https://www.theguardian.com/environment/2019/jul/04/planting-billions-trees-best-tackle-climate-crisis-scientists-canopy-emissions.
  14. Nuwer, R. (2019). What would happen if all the world’s trees disappeared? [online] Bbc.com. Available at: https://www.bbc.com/future/article/20190911-what-would-happen-if-all-the-worlds-trees-disappeared.
  15. Marshall, M. (2020). Planting trees doesn’t always help with climate change. [online] www.bbc.com. Available at: https://www.bbc.com/future/article/20200521-planting-trees-doesnt-always-help-with-climate-change.