Understanding The Carbon Cycle For The Climate Crisis

Do you know how the carbon cycle works? To understand why the climate crisis is happening, it’s extremely helpful for us to have an idea of how the carbon cycle works.

I believe that if we know how carbon gets processed and transferred in nature, we’ll see the impacts of our actions much more clearer. So I set off to refresh my memory about the carbon cycle. Turns out, it’s brilliant!

We wouldn’t exist if we didn’t have carbon. Carbon is the second most abundant element in our body, and it’s a crucial component of glucose – our energy source. It’s not only found in us, but it’s also found all around us. It’s in the animals, trees, grass, oceans, soil, rocks, and obviously, the air.

Nature has an intelligent way of keeping the world’s carbon in balance. Let’s take a layman look at the healthy carbon cycle.

The Carbon Cycle

It all starts with the sun. Through photosynthesis, trees, land and sea plants, and phytoplankton use sunlight and carbon dioxide and turn them into energy, oxygen, and water. Carbon from carbon dioxide transforms into sugars, which provides energy for the plants to grow. By this process, carbon dioxide from the air is captured and “stored” in the plants.

Some of the carbon is also stored in plant roots and passes into the soil. This process is known as soil carbon sequestration. In other words, like forests, the soil is a huge carbon sink too.

When animals eat plants, the carbon stored in the plants enters their body and gets processed into glucose that’s used to keep them alive.

The same process happens when bigger predators or humans consume these animals. Our food sources, be it animal or plant-based, supply our body with nutrients containing carbon, moving the element along in the cycle.

Following consumption, carbon returns to the environment in the form of carbon dioxide when plants, animals, and humans respire.

Of course, carbon is also released as gases like carbon dioxide or methane when things die and decay. If decomposition happens in the soil, part of the carbon remains in the soil, forming humus which gives healthy dirt its nice dark color and provides nutrients for other organisms or plants.

The carbon dioxide released is then taken in by the plants and trees again, and the cycle continues.

A Balanced Cycle Disrupted

In nature, the carbon cycle is stable. Though the amount of carbon dioxide in the atmosphere fluctuates according to the growth and decay of trees and plants, it has never gone above 300ppm in the 400,000 years before 1950. Scientists know this by studying the content of ancient air bubbles trapped in the ice cores. The stable cycle regulates the earth’s temperature – much like a thermostat.

In the ’50s, Charles David Keeling directed a study that monitored the levels of carbon dioxide in the atmosphere at Mauna Loa, Hawaii. For decades, the program has been tracking the carbon dioxide concentrations. This is what it found:

As you can see, the carbon dioxide concentration in the atmosphere has been increasing.

So, what happened in the 1950s?

Carbon dioxide emissions started to spike steeply in the ’50s. There are several reasons for this, but the biggest cause is the burning of fossil fuel. Deforestation and change of land use have also contributed to this increase to a smaller extent.

The Carbon Cycle and Carbon Dioxide Emission

Burning of Fossil Fuel

Over millions of years, dead plant and animal matter pile up in layers where they decay, but the carbon isn’t released into the environment since they’re buried. Eventually, the combination of pressure, heat and time turns them into stores of organic carbon, known as fossil fuels.

Yes, when we burn fossil fuels, we’re burning dead plants and animals accumulated over millions of years. That puts a fresh spin on plastic, doesn’t it? We’re using animal remains (maybe even dinosaurs’) to make disposable containers. That’s some food for thought.

Anyway, when we burn fossil fuels, we’re burning through our ancient carbon stores, releasing carbon dioxide that has been “saved” over millions of years in just a few centuries.

In nature, the carbon cycle balances itself out. Carbon dioxide released from respiration are “processed” by photosynthesis, and even though decomposition releases carbon dioxide, it leaves behind some carbon that’s sequestered by the soil.

But the carbon cycle wasn’t designed to process such great amounts of carbon dioxide and still keep its level at what it used to be.

Deforestation and Change in Land Use

Apart from the burning of fossil fuel, we’re also clearing forests at alarming rates. In Southeast Asia, South America and Africa, tropical rainforests are being burnt or cleared to make way for ranches and plantations or to harvest hardwood.

When forests burn, they turn from a carbon sink, which stores carbon, to a carbon source, releasing carbon dioxide.

With the loss of these trees, we have lesser trees to capture carbon dioxide in the air too. But the problem doesn’t stop there.

When we turn forests into agricultural land, we reduce the soil’s ability to store carbon as a result of a reduction of roots. At farms, we till the soil, this increase decomposition rates and release more carbon dioxide into the air. The absence of cover crops with some agricultural practices also exposes the soil to erosion, which is another source of carbon loss.

Consequences

It’s estimated that 55% of the excess carbon we emit is taken up by land plants and the ocean, leaving 45% in the atmosphere, where they trap heat and raise the earth’s temperature. Do you see the correlation in the graph?

With our continual carbon emission and deforestation, the amount of carbon dioxide in the air will only keep increasing if we don’t move on to renewable sources of energy and reduce our carbon footprint collectively.

As it is, polar ice is melting, and oceans are acidifying. The more acidified oceans are, the more carbon dioxide will dissolve in it. What will happen to our marine wildlife?

On the other hand, the warmer weather brought on by climate change is causing forests to become dryer and more susceptible to wildfires in certain regions.

Just a week ago, the National Weather Service issued the very first “extreme red flag warning” in Los Angeles. Wildfires are raging stronger and spreading faster than before, and their frequency has quadrupled since the ’80s.

What kind of environment are we leaving for our next generations?

Looking at Climate Change Through The Carbon Cycle

I hope that by learning about the carbon cycle, we can see the climate crisis with clearer eyes. Nature is intelligently balanced, but we’ve tipped the balance against our favor.

At the same time, I also hope that you’ll appreciate nature more now that you have a better idea of how the carbon cycle works. I definitely do!

It is imperative that humans protect/create more carbon sinks by preventing deforestation, planting more trees, practicing better soil management and protecting the ocean. But that wouldn’t be enough.

We’ve been producing so much carbon dioxide that planting trees and saving forests alone wouldn’t be enough to reverse climate change.

The problem needs to be stopped at the biggest source – fossil fuel consumption. We need to keep the fossil fuel in the ground and reduce our carbon emission.

It’s terrifying to know that most of the world is still reliant on non-renewable energy.

Things we can do:

• Support politicians and causes that protect the environment, including forests and the ocean – both are carbon sinks!
• Share the knowledge and talk about it
• Support renewable energy
• Lower our carbon footprint in any way we can

Keep sounding the alarm.

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