Why Carbon-Based Life Needs Carbon: the Chemistry of Living Things
For over thirty years climate alarmists have vilified carbon and hid the most important fact: carbon‑based life needs carbon. To remove carbon dioxide (from the atmosphere) is to restrict life.
Carbon has a deep story that connects chemistry, planetary science, and the origins of life itself. Why carbon? Why not silicon, sulfur, or some other element? And how do we know that complex organic molecules—the stuff of life—can arise naturally from non‑living chemistry?
More than 70 years ago, a deceptively simple laboratory setup provided one of the first experimental answers. In 1953, Stanley Miller, working under Harold Urey at the University of Chicago, showed that organic molecules could form spontaneously under conditions thought to resemble early Earth. The Miller–Urey experiment did not create life, but it demonstrated something just as important: the raw molecular building blocks of life can arise from ordinary chemistry, provided carbon is present.
This article is written for a non‑science audience. We will move slowly, build ideas step by step, and focus on intuition rather than equations. We will start with the Miller–Urey experiment, expand into what carbon does chemically, and then connect that chemistry to the three macronutrients that all known life depends on: carbohydrates, proteins, and fats. By the end, the phrase “carbon‑based life” will feel less like a slogan and more like a logical conclusion.
1. The World Before Biology: What Scientists Mean by “Prebiotic Chemistry”
Before there were cells, genes, or metabolism, Earth was just a planet with oceans, gases, rocks, and energy. Lightning cracked through the atmosphere, volcanoes spewed gases, ultraviolet light poured down from the Sun, and the oceans endlessly mixed dissolved chemicals.
Scientists call the chemistry that happened before life prebiotic chemistry. The key question is simple to ask and hard to answer:
Can non‑living chemistry naturally produce the kinds of molecules that living systems use?
To answer that, scientists needed more than speculation—they needed experiments.
photo: Harold Urey
2. The Miller–Urey Experiment: A Landmark Moment
2.1 The People and the Question
In the early 1950s, Harold Urey was thinking deeply about Earth’s early atmosphere. Many scientists believed it was reducing, meaning rich in hydrogen and poor in oxygen. Stanley Miller, a graduate student, asked a bold question:
If we recreate early Earth conditions in the lab, will organic molecules form on their own?
Urey encouraged Miller to try.
2.2 The Setup: A Glass Earth in Miniature
The experimental apparatus was elegant and simple:
- A flask of boiling water represented the early ocean.
- A second flask held a gas mixture of methane (CH₄), ammonia (NH₃), hydrogen (H₂), and water vapor—thought to resemble the early atmosphere.
- Electrodes sent electric sparks through the gas, simulating lightning.
- A condenser cooled the gases, causing them to rain back into the “ocean,” creating a continuous cycle.
The system was sealed and sterilized. Nothing living was introduced.
2.3 The Result: Color in the Water
After a few days, the clear water turned red‑brown. Chemical analysis revealed something astonishing:
- Amino acids, including glycine and alanine
- Other organic compounds built around carbon frameworks
Amino acids are the building blocks of proteins. Proteins are essential to all known life. And here they were—made without biology.
2.4 Why This Mattered
The experiment showed that:
- Organic molecules do not require life to exist
- Carbon‑based molecules can arise spontaneously from simple gases
- Early Earth chemistry could plausibly generate the raw materials for life
This did not prove how life began—but it showed that carbon chemistry naturally moves toward biological complexity under the right conditions.
3. Variations and Extensions: A Richer Chemical Landscape
3.1 Later Experiments
In 1958 and later decades, variations of the Miller–Urey experiment introduced new components, such as hydrogen sulfide, to better mimic volcanic gases. These experiments produced:
- A wider variety of amino acids
- Organic acids, sugars, and nitrogen‑containing compounds
The takeaway was clear: the original experiment was not a fluke. Carbon‑rich environments with energy inputs reliably generate complex organic chemistry.
3.2 Other Routes to Amino Acids
Other chemical pathways, such as the Hell–Bhart–Solinsky reaction, also produce amino acids under plausible prebiotic conditions. Different routes, same outcome: carbon chemistry keeps generating the molecules life needs.
4. Why Carbon? The Chemical Superpower of an Element
To understand why all this works, we need to understand what makes carbon special.
4.1 Four Bonds, Infinite Possibilities
Carbon has four outer electrons available for bonding. This allows it to:
- Bond to four other atoms
- Bond to itself, forming chains, rings, and branches
- Form single, double, and triple bonds
No other element combines these traits so effectively.
4.2 Stability With Flexibility
Carbon bonds are:
- Strong enough to be stable
- Weak enough to be rearranged by chemistry
This balance allows complex molecules to exist without falling apart instantly, while still being reactive enough to support metabolism.
4.3 Carbon as a Molecular Scaffold
Think of carbon as the skeleton of molecules. Other atoms—hydrogen, oxygen, nitrogen, phosphorus, sulfur—attach to this skeleton, giving molecules their specific properties.
Life does not just need atoms. It needs structures. Carbon provides those structures.
5. From Prebiotic Chemistry to Nutrition: The Three Macronutrients
All living organisms on Earth rely on three macronutrients:
- Carbohydrates
- Proteins
- Fats
At first glance, these seem like biological concepts. But chemically, they are all variations on the same theme: carbon plus a few other elements.
6. Carbohydrates: Hydrated Carbon
6.1 What “Carbohydrate” Really Means
The word carbohydrate literally means “carbon plus water.”
Chemically, carbohydrates are made of:
- Carbon (C)
- Hydrogen (H)
- Oxygen (O)
Often in ratios that resemble water (H₂O) attached to carbon.
6.2 Why Carbohydrates Matter
Carbohydrates:
- Store energy
- Provide structural materials (cellulose, chitin)
- Serve as chemical starting points for other molecules
In many ways, carbohydrates are the entry point of carbon into living systems.
7. Proteins: Carbon Frameworks Plus Nitrogen
7.1 Amino Acids as Modified Carbohydrates
Proteins are built from amino acids. Each amino acid contains:
- Carbon
- Hydrogen
- Oxygen
- Nitrogen
Conceptually, you can think of proteins as:
A carbon backbone (like a carbohydrate) plus nitrogen
7.2 Why Nitrogen Matters
Nitrogen allows proteins to:
- Form complex shapes
- Carry electrical charges
- Act as enzymes that speed up chemical reactions
Without carbon’s backbone, nitrogen would not be able to organize itself into functional molecules.
8. Fats: Carbon‑Rich Energy Storage
8.1 The Chemistry of Fats
Fats are composed mainly of:
- Carbon
- Hydrogen
- Oxygen
Some biologically important fats also involve phosphorus, especially in cell membranes.
You can think of fats as:
Carbon chains with attached functional groups
8.2 Why Fats Store So Much Energy
Carbon–hydrogen bonds store large amounts of chemical energy. Long carbon chains mean:
- Dense energy storage
- Waterproof barriers (membranes)
- Insulation and protection
Once again, carbon’s ability to form long, stable chains is the key.
9. A Unifying Pattern: Life as Carbon Plus Modifiers
If we step back, a pattern emerges:
- Carbohydrates: carbon + hydrogen + oxygen
- Proteins: carbon + hydrogen + oxygen + nitrogen
- Fats: carbon + hydrogen + oxygen (+ phosphorus)
Life does not replace carbon—it builds on it.
Carbon is the common denominator. Other elements tune the behavior.
10. From Lightning to Life: Connecting the Dots
The Miller–Urey experiment showed that:
- Carbon‑containing gases plus energy produce organic molecules
- Amino acids emerge naturally from this chemistry
Modern biology shows that:
- Those same carbon‑based molecules form the basis of metabolism
- Complex life is built by rearranging, linking, and modifying carbon frameworks
The continuity is striking. There is no sharp line where chemistry suddenly becomes biology. Instead, there is a smooth progression of increasing carbon complexity.
11. What This Does—and Does Not—Claim
It is important to be precise:
- The Miller–Urey experiment did not create life
- It did not explain consciousness, cells, or genetics
What it did show is something more fundamental:
Given carbon, simple molecules, and energy, chemistry naturally moves toward biological building blocks.
That insight remains one of the most important discoveries in origin‑of‑life research.
Conclusion: Carbon Is Not an Accident
When scientists say that life on Earth is carbon‑based, they are not making a poetic statement. They are describing a chemical necessity. When climate crazies tell you we “must cut carbon” they are, in effect, wanting to cut back life – your life.
Carbon:
- Forms stable yet flexible structures
- Bonds easily with itself and other elements
- Naturally generates the molecules life requires
From lightning in a glass flask to the food on your plate, the same chemistry applies. Life does not merely use carbon—it depends on it at every level. More than 70 years after Miller and Urey watched their clear water turn red, the message still holds: If you want carbon‑based life, you must start with carbon.
Addendum – For good measure, here are a few fun factoids (H/T Arthur Viterito):
About the author: John O’Sullivan is CEO and co-founder (with Dr Tim Ball) of Principia Scientific International (PSI). He is a seasoned science writer, retired teacher and legal analyst who assisted skeptic climatologist Dr Ball in defeating UN climate expert, Michael ‘hockey stick’ Mann in the multi-million-dollar ‘science trial of the century‘. From 2010 O’Sullivan led the original ‘Slayers’ group of scientists who compiled the book ‘Slaying the Sky Dragon: Death of the Greenhouse Gas Theory’ debunking alarmist lies about carbon dioxide plus their follow-up climate book. His most recent publication, ‘Slaying the Virus and Vaccine Dragon’ broadens PSI’s critiques of mainstream medical group think and junk science.