by Dr Farooq A. Lone
Carbon dioxide underpins life and climate alike; once a life-giver, its rapid human-driven release now destabilises Earth’s balance, posing unprecedented risks to civilisation.
When we hear the words carbon dioxide (CO₂), the reaction is often instinctively negative. It is widely portrayed as the villain of climate change, the invisible gas responsible for rising temperatures, melting glaciers, and extreme weather events. Yet this narrow framing hides a deeper truth. Carbon dioxide is not merely a pollutant. It is, quite literally, the foundation of life on Earth.
In his thought-provoking book, The Story of CO₂ Is the Story of Everything, science journalist Peter Brannen invites us to see carbon dioxide not as an enemy, but as one of the most powerful and consequential molecules in Earth’s long history. CO₂ has shaped the planet’s climate, enabled the evolution of life, driven mass extinctions, and now, through human activity, has once again become a dominant force. To understand our present environmental crisis, we must first understand the ancient and intimate relationship between CO₂ and life itself.
Carbon: The Skeleton Key of Life
All life on Earth is carbon-based. From the simplest bacteria to towering forests and human beings, carbon atoms form the backbone of biological molecules, namely proteins, carbohydrates, fats, and DNA. But where did this carbon come from?
The ultimate source is carbon dioxide in the atmosphere. Through the remarkable process of photosynthesis, plants, algae, and certain bacteria absorb CO₂ and, using sunlight, transform it into organic matter. Every bite of food we eat, every tree we see, and even our own bodies are, in a sense, made of ancient air.
Without atmospheric CO₂, photosynthesis would cease. Plants would die, food chains would collapse, and life as we know it would disappear. In fact, if all the carbon dioxide were suddenly removed from Earth’s atmosphere today, the planet would quickly plunge into a deep freeze. Temperatures would fall drastically, oceans would begin to freeze, and most life would not survive. CO₂, therefore, is not optional; it is essential.
Earth’s Climate
Over the 4.5-billion-year history of Earth, levels of atmospheric CO₂ have risen and fallen dramatically. These fluctuations are closely tied to global temperatures. When CO₂ levels are high, the planet tends to be warmer; when they are low, ice ages follow.
In Earth’s distant past, CO₂ concentrations were many times higher than today. During these greenhouse periods, there were no polar ice caps, sea levels were much higher, and tropical conditions extended far toward the poles. Palm trees once grew in regions that are now tundra.
At the same time, the burial of carbon played a crucial role in shaping the atmosphere. Over millions of years, dead plants and algae were buried in sediments, eventually forming coal, oil, and natural gas. This process removed carbon from the atmosphere and stored it underground. As carbon dioxide was locked away, oxygen accumulated in the air, enabling the evolution of complex, oxygen-breathing life, including animals and, eventually, humans.
Thus, the rise of forests, the spread of animals, and the emergence of human civilisation are all linked to long-term changes in the carbon cycle.
Carbon Cycles
Earth’s history also offers cautionary tales. Several times, massive releases of CO₂ have disrupted the climate so severely that life on Earth was nearly wiped out. The most dramatic example occurred around 252 million years ago during the Permian period. Known as The Great Dying, the Permian mass extinction eliminated about 90 per cent of marine species and 70 per cent of land species. Scientists believe this catastrophe was triggered by enormous volcanic eruptions that released vast amounts of CO₂ into the atmosphere over thousands of years. The resulting global warming, ocean acidification, and oxygen depletion proved devastating.
Peter Brannen notes that today, humanity is releasing carbon dioxide at a rate far faster than those ancient volcanic events. According to current estimates, we are emitting CO₂ about ten times faster than during the lead-up to the Permian extinction. This rate of change is what makes the present moment so extraordinary, and so concerning.
An Experiment
What sets the modern era apart is not just the amount of carbon being released, but the speed. Fossil fuels represent carbon that was buried over hundreds of millions of years. By burning coal, oil, and gas in just a few centuries, humans are short-circuiting Earth’s natural carbon cycle.
From a geological perspective, this is an unprecedented experiment. Never before has a single species altered the composition of the atmosphere so rapidly. As Brannen puts it, we are “leaping into the unknown.”
This does not mean that a mass extinction on the scale of the Permian is inevitable. Life is resilient, and Earth will endure. But the conditions that have allowed human civilisation to flourish, stable climates, predictable seasons, and manageable sea levels, are being destabilised. The planet may remain habitable, but it may become far less hospitable for us.
Reframing the CO₂ Conversation
Understanding CO₂ as both a life-giver and a climate driver helps move the discussion beyond simplistic good-versus-evil narratives. Carbon dioxide is not inherently bad; it is a fundamental part of Earth’s system. The problem arises when its balance is disturbed.
The challenge facing humanity is not to eliminate CO₂, an impossible and undesirable goal, but to restore balance. This means reducing excessive emissions, protecting forests and oceans that absorb carbon, and developing cleaner energy systems that align with Earth’s long-term rhythms.
Lessons from Deep Time
Earth’s deep history teaches us humility. The planet has survived far worse than human activity, but past disruptions came at enormous biological cost. By studying these ancient events, we gain a clearer understanding of the risks we face and the responsibility we carry.
The story of carbon dioxide is, indeed, the story of everything: of life’s origins, of climate shifts, of extinction and renewal. Today, humanity has become a central character in that story. The question is not whether CO₂ will shape the future; it certainly will, but whether we will act wisely enough to shape that future ourselves.
(An IAS officer, the author retired as chairman of Jammu and Kashmir Public Service Commission. Ideas are personal.)
