I’m sure you’ve thought of this solution before: stopping climate change by simply planting more trees. Intuitively, it seems like the perfect solution to climate change. After all, isn’t that what trees are for? They soak up our carbon dioxide emissions and release oxygen. It is much cheaper than other methods of carbon capture and would basically get the same results. On paper (pun intended), this would work to balance our emissions. All we would need to do is plant enough trees. But how many trees are enough?
Bill Gates laid out a scenario which explains how many trees it would take to balance America’s CO2 emissions, with some alarming findings. I think it would be more interesting and impactful for you if I adapted his study a little closer to home. All I had to do was adapt his calculations a little and find some newer and more relevant statistics. The average South African citizen emits 6.95 tons of CO2e per year, which is almost three times less than the average American (sitting at just under 20 tons per year). A mature tree absorbs roughly around 4 tons every 40 years. These are the statistics we’ll use to answer our questions.
So, taking these numbers into account and considering average lifespans and area needed per tree, you’d need around 17 acres worth of trees planted in tropical areas (I’ll get to why that is later) to absorb the greenhouse gas emissions produced by the average South African over his/her lifespan. To put that into context, that’s about 13 football fields worth of trees. That doesn’t seem too bad. However, you’re not the only one emitting greenhouse gases. Extend this to the entire population of South Africa and you’d need just under 1 billion acres, or 4 million square kilometres. That’s three and a half times the size of South Africa. All that area just for trees, nothing else. That is an enormous amount of space. And that’s only to offset the emissions of South Africa, the 15th largest emitter in the world. It gets almost exponentially bigger as we go higher up the rankings. (Just for interest’s sake, to absorb the lifetime emissions of the USA we would need half of the world’s landmass).
So, this idea is unfortunately not plausible on a large scale. It’s a pity, because it would have been quite an elegant solution. This is also only one of the few reasons that this idea would not work. There would also be the tricky situation of making sure the trees stay there forever. If a tree is burned down, it releases all of the carbon it has stored over time. Sadly, this is a real concern. Trees are being burned at an alarmingly high rate, especially in places like Brazil and Nigeria, to clear space for farming. The other reason is that, in this scenario, trees only have specific areas they can be planted. Generally, if a tree is planted in colder, snowy regions it causes more warming than cooling. That sounds counterintuitive, but it’s because trees darken the ice and snow beneath them and prevent the reflection of light out into the atmosphere. It is actually only trees in tropical forests that cause a justifiable amount of cooling, so there is only that area with which to work. This is a very limited area, which is already full of wildlife and forests.
As you can see, this convenient idea suddenly became a lot more complicated and regrettably much more unrealistic. However, I don’t think this is an argument to stop planting trees. Planting trees has numerous, extensive benefits for the environment and has tremendous aesthetic value wherever you plant it. We should be planting as many trees as we can. The real problem with trees and climate change is deforestation, and we should rather put our efforts into making sure we stop the destruction of our forests and keep the trees that are still here. I also hope this has put things into perspective for you. After seeing these negligible effects, you may have come to the conclusion that trees just aren’t as effective as you thought they were. They are in fact incredibly effective at absorbing as much carbon dioxide from the atmosphere as they can. Rather, it should help you realise just how much carbon each person emits over their lifetime. It’s a lot. A frightening amount.
Resources:
https://www.worldometers.info/co2-emissions/south-africa-co2-emissions/
How to Avoid a Climate Crisis - Bill Gates