How carbon sinks protect our planet
In geological time, humans have only been around for a flash. But our activity is already endangering the carbon cycle that sustains our planet. Learn more inside.
There should be a filter that lets you view the world according to carbon content — similar to infrared. That picture you shared earlier of your poke bowl would be dripping with white-hot carbony goodness. And is that your new niece? I think she just unloaded some fresh carbon in her diaper (Instagram — if you’re reading this, please return my calls).
Hopefully then, people might get hip to the fact that carbon is everything. You’ve already met one of its celebrity compounds: carbon dioxide — one part carbon to two parts oxygen. This greenhouse gas does a neat job of stopping the earth from freezing over. But you know the story by now: we’re making too much of it. The kicker comes when we also stop the environment from healing itself. In this article, we swivel a light onto carbon sinks, and the lifegiving role they play.
What are carbon sinks?
Carbon is called the ‘king of the elements’ because it’s basically everywhere. In you, me, the ground you walk on, the last meal you ate. And it doesn’t stay still. You may remember the carbon cycle from science class. It explains the timeless passage of carbon through our planet — dropping from the atmosphere onto the land and oceans, through animals and plants, into the earth’s crust, and back into the atmosphere. A vast, planetary symphony that sustains all existence, and stirs in us mortal themes of life, death, and rebirth. Which is all well and good, except for we humans are royally funking it up.
Enter carbon sinks, which have become quite the buzzword. Their exact definition changes depending on who you ask. Ocean Climate calls them “a natural or artificial reservoir that absorbs and stores the atmosphere's carbon with physical and biological mechanisms.” National Geographic is more metrical: “carbon sinks are places that absorb more carbon than they release.” While groupings of sinks can vary by source, NASA divides them into three broad categories: plants, soils, and the ocean.
Now, I don’t love the metaphor, (for me, sinks are cracked, grease-stained kitchen fixtures, not steaming rainforests or infinite oceans) but it fits. Carbon sinks ‘drain’ carbon from the atmosphere. Soaking it up like big sponges. This leaves less carbon dioxide to float around, heating the planet and causing unnatural climate change.
Did you know? According to NASA, “so far, land, plants, and the ocean have taken up about 55% of the extra carbon people have put into the atmosphere while about 45% has stayed in the atmosphere.”
How does this work? Each sink has its superpowers. Forests, with their trillions (yes, trillions) of trees, act as lungs of the earth — breathing in carbon dioxide and storing it via photosynthesis. When a tree, or any organism, dies, it ‘returns’ to the carbon cycle by decomposition, moving carbon downwards through the soil. The ocean traps carbon in a similar way — through death and the food chain — but also via direct absorption, and photosynthesis of plankton. This carbon is swept deep into the ocean’s interior, before settling into the seabed. Together, these sinks help keep the planet and everything on it in balance.
The human impact
Humans don’t create carbon. The amount of carbon on the planet stays essentially the same, and only changes form. The problem is that burning so much fossil fuel is unnatural to the carbon cycle. Fossil fuels are carbon deposits — dead organic matter that carbon sinks had hidden for millions of years, only to be burned by humans and released back into the atmosphere.
The double whammy comes when this extra atmospheric carbon dioxide begins to hurt carbon sinks; essentially stopping the planet from healing itself. While it was commonly believed that sinks would ‘level up’ to deal with excess carbon, like muscles grow to handle extra stress, a recent Stanford study contradicts this. Here, the researchers suggest that even if extra carbon dioxide drove plant growth, this would require more nutrients — thus summoning more carbon that would otherwise remain locked in the soil.
The issue is aggravated by the fact we’re cutting down swathes of forests for land and agriculture. While deforestation is an ancient problem — the planet has lost ⅓ of its forests since the Ice Age — it's worth noting that half of this was in the last century alone. And the oceans have been ‘forced’ to absorb more and more carbon dioxide from the atmosphere, which makes seawater more acidic. This has a strange fallout: stopping key members of the ocean ecosystem — like crabs, corals and snails — from developing shells and skeletons properly. While scientists aren’t sure what the effects of this will be, our bet is that it probably won’t be great.
Sink or swim
It’s easy to take for granted that which we cannot see. It’s why you (generally) don’t find people raving about how much they love oxygen, or actresses thanking hydrogen in their acceptance speech. But carbon is everywhere, and we should be aware, however faintly, of its journey around the world. This carbon-consciousness often underlies a sustainable lifestyle.
Many initiatives are trying to turn the tale; using human enterprise to help the carbon cycle, not hinder it. This can take the form of artificially storing carbon elsewhere, or by supporting the natural sinks we have. Rehabilitating seagrass or planting trees, for example, rebuilds vegetation to fight global warming. Klima lets you invest in such programs, allowing you to choose from diverse schemes close to your heart. While the war against climate change will be won or lost by larger society, we help you play a soldier’s role in defending our planet — or rather, helping the planet defend itself.