We have all seen Walking with Dinosaurs. When it appeared, it was memorable not only because of the technology, but because it managed to make a vanished world feel almost physically present. It also produced a few memorable observations.
One of them was that the Jurassic was a time when life was at its most spectacular.
And it is difficult to argue with the spectacle.
The dinosaurs were enormous. Marine life was extraordinary. Vegetation was abundant and luxuriant. The planet was supporting forms of life on a scale and variety that are difficult to imagine from our comparatively modest present.
The Jurassic was also a world with vastly more atmospheric CO₂ than we have today.
Estimates vary considerably, as estimates of deep geological history inevitably do, but figures in the multiple thousands of parts per million are not unusual. Whatever the precise number, atmospheric CO₂ was several times higher than today’s concentration.
That should at least give us something to think about.
Instead, we tend to treat CO₂ almost exclusively as a pollutant.
We also tend to imagine that the Earth itself is some kind of benevolent goddess, generously providing a uniformly habitable paradise that humans have somehow managed to ruin.
It is a comforting image.
It is also nonsense.
Look around.
Most of the planet is not particularly hospitable.
We tend to think of deserts, the polar regions and perhaps the highest mountains as the obvious exceptions. But those are merely the exceptions we can see.
There is another enormous world beneath the surface of the oceans.
And the oceans cover roughly twice as much of the Earth’s surface as the land does.
That world is not uniformly hospitable either.
There are marine deserts.
There are enormous areas of ocean with very little biological productivity. There are dead zones in which oxygen levels become so depleted that most marine life cannot survive. There are vast stretches of water where the conditions are simply not particularly generous to life.
And yet the oceans are so immense that even these barren regions can be enormous.
The scale of the planet is difficult for us to comprehend.
Take Point Nemo, the oceanic pole of inaccessibility in the South Pacific.
Get yourself there, and the nearest human beings may not be on another island, another ship or even another continent.
They may be orbiting above you aboard the International Space Station.
That is the planet we inhabit.
Not a garden.
A gigantic, violent, chemically complicated ball of rock and water in which life occupies particular niches where conditions happen to permit it.
Earth does not owe life abundance.
Life has to work for it.
And life does extraordinarily well when conditions permit it to do so.
Which brings us back to CO₂.
Carbon dioxide is not some alien contaminant that civilisation accidentally introduced into an otherwise pristine environment.
It is part of the natural carbon cycle.
Plants require it.
More atmospheric CO₂ can, under suitable conditions, increase photosynthesis and improve plant growth and water-use efficiency. The precise effects vary enormously by species, nutrients, temperature and water availability. There is no single magical response.
But the basic fact remains remarkably inconvenient to simplistic narratives:
CO₂ is plant food.
And the history of the planet contains periods when atmospheric CO₂ concentrations were vastly higher than today and life was not merely surviving.
It was flourishing.
Spectacularly.
That does not settle the modern climate question.
It does not mean temperature is irrelevant.
It does not mean every increase in CO₂ is harmless.
It certainly does not mean we should stop measuring, modelling or questioning what is happening to the climate.
But it should make us rather more cautious about describing CO₂ as though it were simply poison.
The Earth is not a delicate porcelain ornament that humans have somehow damaged by breathing too heavily.
It is a dynamic planetary system that has experienced enormous changes throughout its history.
Life has survived ice ages, warming periods, atmospheric transformations, volcanic catastrophes, asteroid impacts and mass extinctions.
And when conditions allowed it, life exploded.
Perhaps the question is therefore not whether the planet is being sufficiently protected from life.
Perhaps we should sometimes ask whether we are creating conditions in which life can flourish.
Because the Earth is not a benevolent goddess.
It is not a paradise we inherited and then carelessly spoiled.
It is a vast, indifferent system.
And life is remarkably good at exploiting opportunities when they appear.
More CO₂ is not the whole story.
But perhaps we should stop pretending that it is the enemy of life.
Sometimes the thing we have been taught to fear is also one of the things life needs most.
https://notalotofpeopleknowthat.wordpress.com/2026/08/07/global-greening-hits-new-record/