Trees – and all other plants – have the unique ability to sequester, aka store carbon. Whilst getting their photosynthesis on, trees take carbon dioxide out of the atmosphere and convert it into sugar and cellulose, and store it in their trunk, roots and other leafy bits. The other, and most important part of this process for us is oxygen, which is given off in the process. It means that we can breathe.
Oxygen is quite a peculiar element to have in our atmosphere; it’s highly reactive and oxidises most elements it comes into contact with. Actually oxygen is too chemically reactive to remain in our air without being continuously topped up by plants, trees and other organisms that photosynthesise. The wonder of life is a balancing act; too little oxygen we wouldn’t be able to survive, too much oxygen we’d also die, either from respiratory tract irritation or by getting eaten by giant flying insects. Yep, 21 percent is the perfect number because about 300 million years ago (when oxygen levels reached 35 percent) there were dragonflies with wingspans the size of an eagle’s.
Anyway, trees are special. To produce 1 kilogram of wood, a tree eats up about 1.47 kilogram of carbon dioxide and converts it into just over 1 kilogram of oxygen, enriching our atmosphere and reducing global warming. When trees are harvested for wood, the carbon, which has been stored, remains safely locked inside the wood for the life of the product. Typically 50% of the dry weight of wood is carbon!
A distinction needs to be made here, between stopping the causes of global warming or simply slowing down the effects. Although trees and wood products store carbon, they do not remove it completely. When the wood degrades all of the carbon that was once locked safely inside is released into the environment again, broken down by microorganisms, or in most cases burnt up in thick clouds of nasty carbon dioxide, methane and even worse -nitrogen dioxide. It is far more preferable to have this carbon stored here on the surface in a nice wooden coffee table or a lush pine forest, rather than having it released into the earth’s atmosphere. Planting more trees, picking wood products over other materials and building long lasting wooden homes are all things that help reduce the amount of carbon in the air and thus reduce global warming. Of course a preventative solution is better, not emitting carbon in the first place would save us a lot of trouble.
In the US, forests store huge amounts of carbon. In fact 10-20 percent of US carbon dioxide emissions are sequestered in forests. It’s a shame that they produce over 5,000,000 kilo tonnes of carbon dioxide per year (2015), not to pick on the States for any particular reason, but the top 10 largest emitter countries account for 67.6 percent of the world total emissions, and the states is number 2 on the list.
In 2015 Indonesia burnt tropical rainforest to make way for palm oil plantations and agriculture, emitting 2.3 million tonnes of carbon per day, which is more than the total carbon emissions of the EU. Vast quantities of tropical forest and peat land were removed, destroying biodiversity and threatening endangered species such as the orang-utan, all in the name of profit, and it’s happening everywhere.
The Amazon rainforest is another example of a forest which has such huge importance to us and is being mindlessly degraded mostly for cows to graze (if you haven’t seen it already cowspiricy is a must watch), but it’s no fun blab on and on about global warming. We have enough of this drama around us in daily life, in the news and on the internet. The point, which has to be made, is that trees are vital to us.
As the biggest plants on the planet, trees give us life. They purify our air, store carbon and supply us with oxygen. Their roots stabilise the soil and allow wildlife to proliferate. They provide us with medicine, materials and tools to make shelter. They create microclimates, which reduce the air temperature in cities by up to 7 degrees so that we don’t get too hot and bothered thinking about all the issues on this warm globe of ours.
So, trees are pretty great. Go help one, go climb one or even better go plant one!