Sep 3, 2024
Why carbon?
In the first post of this series, we explored what carbon is and where it's found. Now comes the inevitable question: why do we talk so much about carbon?
Among all the elements of the periodic table, carbon holds a central place in discussions about climate, energy, and planetary survival.
The answer lies in its role in the greenhouse effect — and the consequences of the imbalance caused by human activities.
The role of carbon in the atmosphere
Earth's atmosphere is composed mostly of nitrogen (78%) and oxygen (21%). Carbon dioxide (CO₂), on the other hand, makes up just 0.04% of the atmospheric volume — a tiny fraction.
Even so, this minuscule trace plays a huge role: it is one of the main gases responsible for the greenhouse effect, helping keep Earth's surface temperature within a range that supports life.
If there were no greenhouse gases, the planet's average temperature would be -18°C. Instead, thanks to the presence of water vapor, CO₂, methane, and other gases, we maintain an average of about 15°C — or +33°C of “natural insulation.”
The issue: excess CO₂
The greenhouse effect is a natural and necessary phenomenon. The problem begins when we add CO₂ to the atmosphere excessively — and that's exactly what we have been doing in recent decades. This excess is mainly caused by two fronts:
• The burning of fossil fuels (coal, oil, natural gas) for energy production, transportation, industry, etc.;
• Deforestation, which releases stored carbon in trees and soils and reduces the capacity for removal via photosynthesis.
A planet out of balance
Historically, CO₂ concentration in the atmosphere remained stable around 280 parts per million (ppm) for thousands of years. But since the Industrial Revolution, this concentration has been rising:
• 1750: 280 ppm
• 2024: 422 ppm
This leap of over 50% occurred in less than three centuries — a blink of an eye in geological terms — and is directly linked to global warming and climate changes we already feel.
Measuring carbon: mass and volume
When discussing carbon, we use two main forms of measurement:
Mass: measured in tons, kilograms, or gigatonnes.
For example: 1 ton of carbon (C) is equivalent to 3.67 tons of CO₂ (because CO₂ is heavier, including two oxygen atoms).
Volume: we use units like parts per million (ppm) to indicate the concentration of the gas in the atmosphere.
There is also a useful conversion:
1 ppm of CO₂ = 2.13 gigatonnes of carbon in the atmosphere
Knowing how to convert between these units helps understand the numbers in reports, carbon credit projects, and public policies.
Conclusion
We talk about carbon because it is, at the same time:
• The foundation of life,
• A planetary temperature regulator,
• And a source of climate imbalance when mismanaged.
In the next post, we'll understand where the planet's carbon stocks are — and why some of them are strategic targets for the carbon market.