Explore Earth's Story

Part 1 A Different Sense of Time

Every one of us has wondered where we came from and what the future holds. This project explores those questions by looking at Earth's extraordinary history—from its formation more than four billion years ago to the challenges our planet faces today.

The story is about much more than climate. It is about geology, evolution, oceans, forests, and ultimately ourselves. Understanding the past helps us understand the present, and perhaps make wiser choices for the future.

When we think of ancient history, we often picture the pyramids of Egypt, built about 4,500 years ago. They seem unimaginably old.

Yet they represent only the very beginning of recorded human history. Civilisations developed writing around 5,000 years ago, allowing events to be recorded rather than passed on by memory alone.

Earth's story is vastly older. Our planet is about 4.5 billion years old—roughly one million times older than the Great Pyramid.

To understand today's climate, we need to think on the timescale of the planet itself.

Take a moment: 

Human history fills libraries. Earth's history fills the rocks beneath our feet.

A Planet Born from Stars

Earth formed about 4.57 billion years ago, at roughly the same time as the Sun, from a cloud of gas and dust left behind by earlier generations of stars. Many of the elements that make up our bodies—carbon, oxygen, iron and calcium—were forged inside those ancient stars before being scattered across space by exploding supernovae.

In a very real sense, we are made of stardust.

The universe itself is almost 14 billion years old, making our planet part of an even larger cosmic story.

The Young Earth

The Earth that formed was nothing like the one we know today. Its surface was molten, constantly reshaped by volcanic activity and frequent collisions with asteroids. Gradually the planet cooled, allowing a solid crust to form.

As temperatures fell, water condensed to create the first oceans. These oceans became the cradle of life, setting the stage for everything that would follow.

Although the details are still being studied, this remarkable transformation—from a fiery young planet to one capable of supporting life—is one of the most important chapters in Earth's history.

Life Changes the Planet

Early life was simple, but its impact was profound.

Among the most important organisms were cyanobacteria, microscopic cells that used sunlight to produce energy through photosynthesis. As a by-product they released oxygen.

At first, this oxygen reacted with dissolved iron in the oceans, forming the spectacular banded iron formations that are mined around the world today. Once the available iron had been oxidised, oxygen began accumulating in the atmosphere.

This slow transformation changed Earth's chemistry forever and made complex life possible. The air we breathe today is the legacy of those tiny organisms that lived billions of years ago.

Pause for reflection:

Every breath you take contains oxygen released by tiny organisms whose ancestors transformed Earth billions of years ago. We are literally breathing the legacy of ancient life.

An Oxygenated World

Over billions of years, tiny organisms transformed the chemistry of our planet. Oxygen gradually accumulated in the atmosphere, creating conditions that allowed increasingly complex forms of life to evolve. 

Earth's history has not been a smooth progression. It has experienced periods of extreme heat, global ice ages and dramatic changes in the atmosphere. Yet life persisted through each challenge, adapting and evolving as conditions changed.

By around 540 million years ago, the stage was set for an extraordinary explosion in the diversity of life. Compared with the age of the planet, however, humans are very recent arrivals.

Pause for reflection

Every breath you take contains oxygen released by tiny organisms whose ancestors transformed Earth billions of years ago. We are literally breathing the legacy of ancient life.

A Goldilocks Planet

Earth is often called a Goldilocks planet because it possesses a remarkable combination of characteristics that make life possible.

We orbit at just the right distance from the Sun for liquid water to exist. Our atmosphere provides the gases life depends upon while protecting us from harmful radiation. A strong magnetic field shields the planet from the solar wind, and plate tectonics continually recycle nutrients while reshaping the continents.

Even our Moon plays an important role by stabilising Earth's tilt and creating the tides that have influenced life for hundreds of millions of years.

None of these factors alone would be enough. Together, they have made Earth an extraordinarily hospitable home for life.

The First Common Ancestor

Although millions of species have lived on Earth, every living organism is thought to share a common ancestry.

Scientists refer to this earliest known ancestor as LUCA—the Last Universal Common Ancestor. It was not the first living thing, but the organism from which all modern life is believed to have descended.

Whether it is a towering eucalypt, a whale, a mushroom or a human being, every living species carries traces of this ancient relationship. The diversity of life we see today has grown from one shared beginning over billions of years of evolution.

Life Becomes More Complex

Simple cells eventually evolved into more complex cells with internal structures, allowing new forms of life to emerge.

Over immense periods of time, single-celled organisms joined together, specialised and formed multicellular plants and animals. Evolution did not follow a straight line; countless species appeared, flourished and disappeared as Earth's environments continued to change.

The story of life is therefore one of continual experimentation, adaptation and resilience—a process that continues today.

Life Moves Onto Land

For much of Earth's history, life was confined to the oceans.

Eventually plants colonised the land, followed by insects, amphibians, reptiles and, later, mammals. Forests spread across the continents, soils developed and entirely new ecosystems emerged.

Life itself began reshaping the planet. Plants altered the atmosphere, stabilised soils and influenced climate, while animals dispersed seeds, recycled nutrients and became part of increasingly complex ecological communities.

By this stage, Earth had become recognisably alive.

A thought :

Life did not simply adapt to Earth. Over billions of years, life has helped shape the atmosphere, oceans and even the rocks beneath our feet. Earth and life have evolved together.

Life Depends on Connections

No living organism exists in isolation. Every plant, animal, fungus and microbe depends on countless interactions with others. Together they form ecosystems—complex networks that recycle nutrients, regulate gases, and maintain the conditions needed for life.

The remarkable balance of these relationships has developed over billions of years. Even the smallest organisms play an essential role, often supporting countless larger forms of life.

Healthy ecosystems are resilient, but they are also interconnected. Disturbing one part of the system can have consequences that spread far beyond the original change.

Reading Earth's History

Earth has kept an extraordinary record of its own past.

Layer upon layer of sediment has preserved fossils, minerals and chemical clues that allow scientists to reconstruct ancient environments and the evolution of life. Different rock layers tell us about changing climates, extinct species, volcanic eruptions and the formation of valuable resources such as coal, oil and iron ore.

Like the pages of a vast history book, these rocks reveal how our planet has changed over hundreds of millions of years.

A Planet Under Constant Construction

Although mountains appear permanent, they are constantly changing.

Wind, rivers, glaciers and the sea slowly wear them down, carrying sediment across the landscape. Meanwhile, deep within the Earth, tectonic forces continue to build new mountain ranges as continents collide and the crust is uplifted.

The mountains we admire today are simply the latest chapter in a cycle of erosion and renewal that has been repeated many times throughout Earth's history.

Our seemingly solid planet is, in reality, constantly being reshaped.

When Everything Changed

Most changes in Earth's history have been gradual, but occasionally dramatic events have transformed the planet in a geological instant.

One of the best-known occurred 66 million years ago when a large asteroid struck near what is now Mexico. The impact triggered global fires, dust-filled skies and the collapse of many ecosystems, leading to the extinction of around three-quarters of Earth's species, including all non-avian dinosaurs.

Mass extinctions are reminders that life on Earth can be remarkably resilient—but also surprisingly vulnerable.

Recovery and Renewal

The history of life has not been a steady climb. Diversity has increased over time, but the journey has been interrupted by repeated mass extinctions caused by volcanic eruptions, changing oceans, asteroid impacts and other natural events.

Each time, life recovered. New species evolved, ecosystems rebuilt themselves and biodiversity gradually increased again.

The graph on this slide tells an optimistic story: despite enormous setbacks, life has repeatedly found ways to adapt and flourish.

It is a reminder that change is inevitable—but the speed and scale of change matter enormously.

Pause and reflect, before Chapter 2  - coming soon

Earth's history teaches two important lessons. Change is normal—but rapid change can reshape ecosystems for millions of years. That perspective becomes especially important as we begin looking at today's changing climate.