There is some disagreement among scientists regarding how planting enough trees can help to reduce climate change. Here’s why.
How do plants help to reduce global warming?
Plants help to reduce global warming by absorbing carbon dioxide through photosynthesis and turning it into oxygen. Photosynthesis is the process in which green plants transform light energy into oxygen and organic compounds. In fact, plants are the main way that our planet recycles CO2 back into oxygen. Carbon dioxide is a greenhouse gas that traps heat from the sun and thus warms up the planet. Therefore, more CO2 in the air raises global temperatures, and turning it back into oxygen reduces global warming.1
Plants also enrich the soil by providing it with organic matter that microbes and bacteria need. That, in turn, helps the soil absorb more carbon dioxide, reducing greenhouse gases in the atmosphere.2
Why does planting trees help to slow climate change?
Trees are currently the most efficient and natural method to remove and store carbon from the air. Between 2001 and 2019, forests around the world absorbed over 15 billion metric tons of carbon dioxide from the atmosphere every year, according to research by NASA.3
Trees do more than just recycle carbon dioxide into oxygen. They also use the carbon they absorb to build their trunks and leaves. We call this carbon sequestration. It makes trees a fantastic store for carbon that can be locked up for hundreds of years.4
Can we plant enough trees to stop global warming?
There is some disagreement among scientists over whether we can plant enough trees to stop global warming. Some say that planting over a trillion trees would heavily contribute to limiting the damage from climate change. Others, however, think that we need to focus on limiting carbon dioxide emissions instead. We must listen to both sides of the debate.5
If we planted enough new trees to cover an area the size of the United States, we could erase 100 years worth of carbon dioxide emissions. This was the conclusion of research published in 2019 by scientists who urged a massive tree-planting program. The new trees would absorb and store enough carbon to reverse new emissions over the last few decades, according to the report.6
But trees take time to grow, they need a lot of water and land, and they do not store carbon permanently. Many scientists say that we cannot stop global warming just by planting trees without reducing carbon emissions.7
Planting a lot of trees would help to reduce global warming, but it would not stop it. Therefore, we need to also severely limit our carbon dioxide emissions.
- Bassham, J.A. and Lambers, H. (2019). photosynthesis | Importance, Process, & Reactions. In: Encyclopædia Britannica. [online] Available at: https://www.britannica.com/science/photosynthesis.
- 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.
- https://jpl.nasa.gov (n.d.). NASA Satellites Help Quantify Forests’ Impacts on the Global Carbon Budget. [online] NASA Jet Propulsion Laboratory (JPL). Available at: https://www.jpl.nasa.gov/news/nasa-satellites-help-quantify-forests-impacts-on-the-global-carbon-budget.
- unece.org. (n.d.). Carbon Sinks and Sequestration. [online] UNECE. Available at: https://unece.org/forests/carbon-sinks-and-sequestration.
- 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.
- NatGeoUK (2019). How to erase 100 years of carbon emissions? Plant trees—lots of them. [online] National Geographic. Available at: https://www.nationalgeographic.co.uk/environment-and-conservation/2019/07/how-erase-100-years-carbon-emissions-plant-trees-lots-them.
- Discover Magazine. (2019). We Can’t Just Plant Billions of Trees to Stop Climate Change. [online] Available at: https://www.discovermagazine.com/planet-earth/we-cant-just-plant-billions-of-trees-to-stop-climate-change.