Introduction: The Smallest and Greatest Things That Change the World

Part 1: Lessons from the Past
1 The greatest environmental change on earth
2 Plants Conquer the Continent

Part 2: Humanity Dominates the Elements
3 The destructive cycle of humans, carbon, and energy
4. How to find the cause of climate change
5 Nitrogen, the magical Goldilocks element
6 people, irreplaceable white gold
7 Water, the core of terrestrial life

Part 3: The Path to the Future
8 Biogeochemical Luck
9 Puzzles Still Remaining

Acknowledgements
annotation

Three Lifeforms and Five Elements That Changed the Earth

The 4 billion-year history of life on Earth is a drama of continuous change and innovation.
And at the center of that drama are five elements: hydrogen (H), oxygen (O), carbon (C), nitrogen (N), and phosphorus (P).

Hydrogen, along with oxygen, forms water and is an essential component of almost all organic molecules.
Oxygen is also a component of water and is essential for breathing life.
Carbon is the 'skeleton' of biomolecules, used to form various molecular structures.
Nitrogen is a key component of proteins (amino acids) and DNA.
Phosphorus is a component of ATP, an energy carrier, and cell membranes.
How well we secure these elements, which make up 99% of the cells of all living organisms, determines the survival and prosperity of living organisms.
In Earth's long history, three types of life have achieved remarkable success in this endeavor.
Bacteria, terrestrial plants, and us humans.
These three protagonists not only became winners of evolution by achieving remarkable innovations in the use of elements, but also became 'World Changers' who changed the environment of the Earth itself.

This book traces how life has utilized five key elements to thrive and drive global change.
What can we learn from this as we bring about yet another transformation on Earth?

Life's Great Innovations and Unexpected Catastrophes

The first world changer was Nam Se-gyun.
The bacteria were able to prosper enormously by developing a method of photosynthesis, which uses solar energy to capture carbon from seawater to create nutrients, and by fixing nitrogen from the atmosphere.
Cyanobacteria released massive amounts of oxygen as a byproduct of photosynthesis, turning Earth, which had been almost oxygen-poor until then, into an oxygen-rich planet.
This 'Great Oxidation Event' set the stage for the emergence of multicellular life forms, including humans, but ironically, it was a huge environmental disaster for the anaerobic life forms that made up the majority of life on Earth at the time.
Most of those that could not survive in oxygen-rich environments became extinct, and today they remain only in limited environments such as deep-sea hydrothermal vents.
The second world changer was terrestrial plants.
The ocean is full of water (oxygen and hydrogen), and carbon and nitrogen can be obtained through photosynthesis and nitrogen fixation.
But phosphorus was very rare in the sea.
Because phosphorus is contained in rocks, to obtain phosphorus one had to go on land and access the rocks.
About 2 billion years after the cyanobacteria, terrestrial plants did this.
Plants have evolved the ability to use their roots to extract essential phosphorus from rocks and to draw up water.
As plants spread across the globe, the Earth became a truly green planet.
But the explosive growth of plants has also brought about environmental disaster.
As a result of absorbing large amounts of carbon dioxide from the air for photosynthesis, the greenhouse effect that kept the Earth warm weakened, and the Earth began to gradually cool down.
About 100 million years later, the Earth had cooled enough to cause most of the rainforests to disappear.

The third is us humans.
Since humans discovered how to use carbon energy, they have been releasing carbon into the atmosphere at an incredible rate.
Plants have lowered carbon dioxide levels by 36 ppm every million years, while humans have raised carbon dioxide levels from 280 ppm to 416 ppm (as of June 2020) in just 200 years, and are continuing to increase them by 4 ppm each year.
The global average temperature has risen by 1.1 degrees Celsius in 100 years, and may rise to 3.8 degrees Celsius by the end of the 21st century.
The pattern of innovation in elemental use becoming an environmental disaster is repeating itself.

Humanity's Success and the Broken Elemental Cycle

Humanity has also achieved unprecedented success in securing water (oxygen and hydrogen), nitrogen, and phosphorus, and here too, similar side effects are occurring.
Until the 20th century, only bacteria such as cyanobacteria could fix and utilize nitrogen in the atmosphere.
In the early 20th century, Fritz Haber invented nitrogen fixation, allowing humans to produce nitrogen fertilizers at will, which led to a dramatic increase in food production.
But now we are overusing nitrogen fertilizers as much as we can get.
Of the nitrogen fertilizers spread on farmland, only about 13 percent become nutrients and reach people, and the rest flows into rivers, oceans, and the atmosphere, causing pollution.
Phosphorus is a more precious element than nitrogen in nature.
So plants have evolved ways to use phosphorus without wasting any of it.
Phosphorus was so precious to humans that it was called "white gold," and animal bones and the sedimentary excrement of seabirds were the only ways to obtain high concentrations of phosphorus.
Production has now increased significantly, with phosphorus ore being mined in West African mines.
However, the fact remains that phosphorus, unlike fossil fuels, is a finite resource that cannot be replaced and cannot be artificially produced like nitrogen fertilizer.
Before the phosphorus mines run dry, we must learn how to use phosphorus as efficiently as plants.

We also need to be more efficient in our water use.
Humans use about 4 trillion cubic meters of water a year.
This is enough to cover the entire United States by about 50 centimeters, and most of it is used for agricultural purposes.
Even in arid lands, huge amounts of water are pumped from underground to support farming, and as a result, the water level in groundwater aquifers is falling every year.
Climate change, which will accelerate in the future, is an issue that cannot be overlooked as it will make water supply more difficult.

Other futures we can go to

Neither bacteria nor terrestrial plants have escaped the disasters brought about by their own success.
However, the author says that humans have two special advantages over the previous two beings.
First, we have the ability to learn from the past and predict the future.
Second, and more importantly, the environmental problems we face do not arise from internal metabolism, which is essential for survival, as in bacteria or plants, but rather from readily replaceable external energy consumption (primarily fossil fuel combustion).
Bacteria had to release oxygen to survive, and plants had no choice but to absorb carbon dioxide.
But not humanity.
We can get the energy we need without emitting carbon dioxide.
We can change humanity's linear way of using elements into a circular way.
"Elemental" presents a vision for the future of humanity at this very point.
If we can break the cycle of energy consumption and carbon emissions and restructure the element cycle in a sustainable way, we can continue to prosper without repeating tragic patterns.
The path may not be easy, but it is a path of hope that our ancestors could not choose.
If we can anticipate the future and change our behavior, we can move toward a different future.
This book will serve as a timely guide to that path.