Life itself reveals the debt owed to carbon dioxide.
Billions of years ago, Earth was a volcanic hellhole, dominated by oceans saturated in dissolved iron and an atmosphere thick with CO₂. The rise of photosynthesis fundamentally re-engineered a sterile rock devoid of life into a biological wonderland.
The early Earth was suffocating in a toxic fog of CO₂ and methane, with virtually no free oxygen. Yet for the earliest microscopic life forms, CO₂ was not a waste product, it became a goldmine.
Carbon is the ultimate molecular building block because of its ability to form stable, complex chains and rings. Primitive life found a way to harness environmental energy to break apart CO₂, unlocking the carbon into organic molecules to build cellular structures. This is how complex multicellular life emerged at all.
Through this process, CO₂ became the universal foundation for life. However, the earliest forms of photosynthesis were limited and relied on scarce compounds like hydrogen sulfide to provide the electrons needed to fix carbon. Future life would need a more abundant source of hydrogen and electrons to fix carbon. That source was water.
This revolution occurred around 2.4 billion years ago with the evolution of cyanobacteria. These pioneering organisms developed a mechanism known as oxygenic photosynthesis, which allowed them to tap into a nearly infinite resource of water (H₂O).
To extract electrons and protons from water to fuel the synthesis of sugars, cyanobacteria had to break apart one of the strongest bonds in nature. They used a catalyst known as the 'oxygen-evolving complex' (anchored by manganese atoms) to split H₂O into its component forms.
Hydrogen atoms were stripped of electrons to convert carbon dioxide into biomass. The oxygen atoms, which had been tightly bound and embedded within water molecules, were no longer needed. Left without their hydrogen partners, these oxygen atoms paired up to form molecular oxygen (O₂), and they were cast aside as a toxic metabolic waste product.
This newly liberated oxygen did not immediately accumulate in the atmosphere. Like all subsequent life forms, the story had to begin in the oceans. The ancient oceans were saturated with dissolved ferrous iron, spewed out from undersea hydrothermal vents. In a world without oxygen, iron remained perfectly soluble, turning the oceans a dense, murky green.
As cyanobacteria pumped free oxygen into the oceans, it immediately reacted with the dissolved iron, turning soluble iron into insoluble iron oxides, which we know as rust. For hundreds of millions of years, the oceans acted as a giant planetary sink, capturing the toxic oxygen and raining rust onto the seafloor.
These massive, compressed deposits are still preserved today as the Banded Iron Formations, which provide modern humanity with the entire primary source of iron ore. They are the basis for every modern city, every house and skyscraper, every motor vehicle, and everything we call modern. It all came from iron dissolved in the oceans.
The oceans eventually ran out of iron sinks and free oxygen began to saturate seawater for the first time, and bubbling up into the atmosphere.
This was the Great Oxidation Event, which was catastrophic for dominant anaerobic life, and triggered the first mass extinction. It cleared the stage for the rise of a modern world. Atmospheric oxygen led to the formation of the ozone layer, shielding the surface from ultraviolet radiation and allowing life to leave the oceans.
Blackening CO₂ as the devilish engine of climate collapse is taking the world down a path into ignorance and backwardness. This recent ideology has a life of its own, embedded in social forces of globalism and driven by a corporate lust for endless riches.
Ultimately, a microbe transformed a rust-choked planet into an oxygen-rich cradle for complex life.