How Trees Help Us Fight Climate Change From Both Ends
The magic of trees is they help stop climate change while also helping us adapt to its inevitable effects
Trees are incredible. Not only do they produce the air we breath, provide vital wildlife habitats and resources like food, fuel, paper and timber, they are also our best friends when it comes to tackling climate change.
Trees mitigate climate change by absorbing carbon, and they also help us adapt to the effects of climate change in at least three ways.
But first, we need to explain a bit about mitigation and adaptation.
Two ends of the climate challenge (explained with a flooded bathroom)
When it comes to climate change solutions, there are two main aspects:
- Mitigation means reducing carbon pollution, and even removing it from the atmosphere, to slow down, reduce, stop or reverse climate change. It’s fixing the root of the problem.
- Adaptation means making changes to deal with the impacts of climate change and make a climate changed world more liveable. It’s making the best of a bad situation.
Both mitigation and adaptation are essential.
If climate change is a flooded bathroom, then mitigation is turning off the taps (cutting emissions) and bailing out the water (carbon removal and storage). Adaptation is turning off the electric, salvaging your sodden items, opening the windows and alerting the neighbours in the apartment below who probably now have a leaking roof…
But there is a tension between them.
We need both, but with finite resources there is competition for funding, attention and effort spent on one or the other. If we focus on adaptation, then that’s less time/money/energy spent on mitigation, which means the problem is getting worse even as we’re trying to adapt to it. We’re sorting out the bathroom while the taps are still running! But if we focus on mitigation, it ignores the fact that climate change is already causing suffering now (mostly to people already struggling with poverty) and will still get lots worse, even if we mitigate like hell, and we’re not prepared at all for the onslaught.
If we stretch our example even further, it’s like you know these taps are somehow going to take days to turn off but you still haven’t found another bathroom to use or protected the rest of the house.
Anyway, back to trees. The wonderful thing about trees and forests is they help with both mitigation and adaptation simultaneously.
Let’s explore how.
The way trees help us mitigate climate change
As you probably remember from school, plants (including trees) absorb carbon dioxide via photosynthesis — the process that turns sunlight, water and carbon dioxide into energy for the plant and also emits oxygen as a happy byproduct.
Trees absorb carbon dioxide through their leaves and turn them into sugars needed for them to grow. As the tree grows, it is able to lock away the carbon in its branches, roots and trunk, playing a key role in combating the effects of global warming.
But how much CO2 do trees absorb?
How much carbon a tree absorbs varies a lot based on the tree species, its age, the size, the type of soil and other factors. This is why there are lots of different answers to this question on Google. The that a mature tree absorbs about 22 kilograms of CO2 per year. that a young native woodland can store 400+ tonnes of CO2 per hectare.
Trees and forests do not store the carbon for ever though. When they decompose or burn, the carbon they had absorbed through their life is released back to the atmosphere. This is part of the natural carbon cycle. But unsustainable human activity has sent this into overdrive.
Huge areas of forest are destroyed every year, mostly to make room for cattle ranching or cash crops. Deforestation of global greenhouse gas emissions. Ending deforestation to limiting climate change to 1.5C.
Warning: Planting trees is absolutely not a replacement for eliminating fossil fuel use
Agriculture, forestry, and other land use can provide large-scale emissions reductions and also remove and store carbon dioxide at scale. However, land cannot compensate for delayed emissions reductions in other sectors.
(my emphasis)
Some people, who are invested in continued fossil fuel use, try to suggest that we can continue burning coal, oil and gas and just plant more trees to soak up the carbon. But this is not true. The climate crisis is too urgent, the carbon cycle is a like this, and even if it were that simple, we would soon run out of land to plant enough trees to keep up with the emissions.
To address climate change, we have to quickly phase out fossil fuels to reduce emissions to net zero (very close to absolute zero) by 2050 at the latest and also end deforestation and plant more trees and woodlands at the same time. It has to be both.
Luckily, protecting and planting trees also helps us adapt to the effects of climate change while we’re working on mitigation.
3 ways trees help us adapt to climate change
1. Preventing floods
Flooding happens after heavy rain when rivers burst their banks or drainage systems overflow. Trees can help prevent this by absorbing much of the excess water before it flows into drains or rivers. The surface roots quickly absorb water as it seeps into the ground and the deep tap roots use up some of the groundwater, allowing the soil to absorb more.
As well as simply drinking a lot of water, trees also change the physical structure of the soil. The dropped leaves and twigs add organic matter, which allows the soil to hold more water — and the little microbes that eat them create tiny tunnels in the soil, helping water seep in more effectively.
found that strategic tree-planting can reduce the ‘peak height’ of floods in downstream towns by up to 20%.
2. Preventing droughts
Maybe it’s not that surprising that trees are a natural flood defence, because they drink a lot of water. But get this: they also help to prevent droughts.
Trees and forests play a vital role in the water cycle. As well as drinking water through their roots, they release water through their leaves into the air — a process called transpiration. And they catch rain on their leaves, which evaporates back into the air to form rainclouds — although often the wind carries them and the rain falls somewhere else. is driven by this combined process of evapotranspiration by forests.
With more research, it may even be possible to in other places, using wind currents to transport the water vapour to where it’s needed most. This could be a gamechanger as climate change gets more serious.
3. Cooling urban temperatures
Cities tend to be a few degrees warmer than the surrounding rural areas, due to something called the .
That may not sound too bad, but it causes health problems and even deaths in the summer and increases energy demand for air conditioning — which bumps up costs and causes more carbon emissions. In the than hurricanes, floods and lightning combined. In the UK we faced scorching for the first time in 2022.
Grey buildings and roads absorb more light than green vegetation does, emitting more heat and warming up the city. Urban trees (along with gardens, parks, green-walls and green-roofs) counter this through the power of evapotranspiration. Their leaves release water vapour, cooling the surrounding air. And of course, trees also provide shade.
Final thoughts
Trees are our best friends when it comes to climate change because they help us fight the problem from both ends — both mitigation and adaptation.
As an individual, how can you help?
- Choose local sustainable wood products or FSC certified ones, and recycled paper products (e.g. notebooks, cards, toilet rolls)
- Avoid or at least limit beef consumption, as most tropical forests are cleared for cattle ranching
- Look for sustainably sourced palm oil, coffee and soya as these products often contribute to deforestation
- When disposing of wood products, get them recycled rather than thrown in landfill, and recycle paper and cardboard
- Lobby your local council to plant more trees in your neighbourhood, and your political representatives to vote on national policies to protect forests in your country and overseas
- Donate to charities that protect and plant trees, or join one of their tree planting days
If you enjoyed this article, follow me for more Medium stories about environmental issues, climate change and how society is dealing with it.
