July 26, 2024

Carbon Sinks: Analyzing Some of the Most Effective Methods to Fight Climate Change

By Ethan Y. (G7)

When I ask you what you think is the best way to tackle the current climate change crisis, what do you think about? A lot of people think that planting trees is the best way to fight climate change is by planting a lot of trees. Like, A LOT of trees. But is this really the most effective strategy?

Trees can work. The world’s forests are already absorbing a net value of 8-9 billion tons of CO2 per year, which already cuts a decent portion out of our emissions. On top of that, they also produce oxygen, allowing many organisms, including us, to breathe. Because of this, they are often referred to as carbon sinks, which absorb carbon dioxide and either put it away or use it, and can be an extremely effective way to combat climate change.

As trees and forests absorb more carbon dioxide than they release, they are a carbon sink: think about it like they are the drain that CO2 flows into, never to appear again. They have a negative net CO2 release rate, so they can help neutralize our positive net CO2 output. Because of this, they also go by the name “carbon sequestration”.

Great! So let’s find out how many trees we will need to plant in order to have a net 0 CO2 emission rate. First, how much CO2 do we emit? Between cars, factories, and everything else, we can reasonably estimate the world emits 38 billion tons of CO2 per year. So how much do trees combat this? On average, one tree absorbs 48 pounds of carbon dioxide, and either uses it or puts it in the soil. In fact, soil itself can be considered a carbon sink, but it is also part of a forest ecosystem. So how many trees will we need? 2 trillion. Looking at that number, even if some of the work is already done for us, we see that our plans to plant more trees seem like something completely impossible.

On top of that, a good chunk of the carbon dioxide that forests capture is often released, when trees die or get burned in a forest fire. While trees do consume some CO2, not all of it is consumed but instead stored. This is significant because it means that CO2 hasn’t disappeared, but only put somewhere else, even though it does not contribute to climate change there. At any time, a wildfire can come along and release all of that CO2 stored by the tree, which can be more than half what it absorbed.

However, are forests the only carbon sinks? Well, oceans are another one. Oceans, just like forests, also absorb carbon dioxide. Just like in forests, phytoplankton(plant plankton) in oceans can absorb carbon dioxide and release oxygens, just like what trees do. These, however, use more of the carbon dioxide they absorb and therefore have less of a release factor. Aside from that, though, oceans also have another tool: chemical reactions. Carbon dioxide can be dissolved in water, which the oceans have no shortage of. In fact, the world’s oceans absorb more carbon than the world’s forests, but they do cover a much larger area. Even though there cannot be much done about expanding oceans, they do cut a huge hole in the large number of trees we need to plant, 30 percent of the world’s emissions, or 11.4 billion tons of CO2!

So, if we use the oceans, we’ll be fine, right? Well, it’s not that simple. You see, carbon dioxide absorbing into water is not necessarily a good thing. Even if it does prevent the greenhouse gas from having negative effects in the atmosphere, it doesn’t mean that it can still cause problems in the water. The reaction that was mentioned before, carbon dioxide mixing with water, forms carbonic acid. Carbonic acid, being acidic, lowers the pH of the water causing a phenomenon called ocean acidification. Not only does this harm many organisms which may be specialized for the higher pH from before, but it also harms many calcifying organisms which cannot form their shell, most notably of these coral. Overall, having the ocean absorb CO2 can help, as this does function as a carbon sink, but tossing our problems somewhere else does nothing to fix them.

Well, here’s another idea: We build our own carbon sink. The idea is already out there, and it is actually a current work in progress. Artificial carbon sinks, most notably Direct Air Capture(DAC) technologies are much more expensive than saplings, but work much better, too. They directly capture CO2 from the air, as suggested by the name, and store it in a variety of places, including underground or in the deepest parts of the ocean, or recycling it. Recycled carbon dioxide can be used in materials such as plastics, or into net zero fuels which, even if they release carbon dioxide, the carbon dioxide released was not created but only reused. On top of that, their positioning can help, too, as they can be placed in areas that emit a lot of carbon dioxide such as factories, as putting them in more polluted air allows them to capture more of that pollution.

Artificial carbon sequestration can also be a booster to natural versions, as some types of tree fertilizers can also boost their capabilities to absorb carbon dioxide. Because of this, we can decrease the number of trees required to help us get to net zero carbon emissions.But, the big question is, are all of these methods enough? Well, it’s not likely. Carbon sinks will play a major role in our goals of net zero, but are not the entire solution. At our current rate, we seem to be heading towards catastrophe! So, on top of that, it is always a good idea to try our best to minimize our CO2 output. While carbon sinks themselves may not be able to fix the problem, carbon sinks, in conjunction to saving energy, renewable energy, less natural gas, coal, and oil usage, and many other things, can.