The following timeline in no way claims to supersede the thousands of books written about human history. Its aim is to give a global vision of the problem and to replace humans and the modern era into the context of our planet’s vast history.
The discontinuous purple line represents the whole of history, from the Big Bang to present times. The grey area at the end of each section of the line corresponds in time to the beginning of the next section. Key stages are listed underneath the main purple timeline.
Dates are indicated in before present up to the last two lines, then in A.D.
Some salient points in a nutshell:
The Earth was formed 5 billion years ago (-5 Ga).
Life appeared on Earth 3.8 billion years ago (-3.8 Ga).
Apes evolved into humans 2.5 million years ago (-2.5 Ma).
The Metal Ages started 5,000 years ago (-5ka).
The Industrial Age started about 300 years ago.
If you convert this time scale down to one that is more easily comprehended, e.g. the 24-hour day.
If you consider that the Earth was formed 24 hours ago, then humans appeared 43.2 seconds ago.
If you consider that humans appeared 24 hours ago, then the Metal Ages started less than 3 minutes ago, and the Industrial Age, 10 seconds ago.
And now that humans are put back into the proper context, we should all be feeling a bit humble.
We’ll just mention that humans have gone through hotter periods and glacial periods, and have always adapted. A “glacial period” is nothing more than a succession of hotter and colder periods, where the mean is rather colder than warmer. Each sudden climate or geological change brought about an extinction of some species, followed by the evolution of the surviving species.
The following graphs are based on the graphs Les climats passés de la terre published by the Société Géologique de France (Editions Vuibert). I have just added a few notes to help situate humans throughout the temperature variations.
The graph below is a reproduction of the one published in n°394 Octobre 2003 of the French national demographical studies institute INED, signed Jean-Noël Biraben et entitled Évolution du nombre des hommes (Evolution of the number of humans).
The fluctuating numbers of humans along the horizontal lines are labelled "climate fluctuations". Outside of these periods of continual adaptation, as a function of available resources and of the climate, there are two periods of heavy growth:
Climate does not appear to have been a factor in human development during the Upper Paleolithic period. The growth in numbers seems rather to be due to the arrival of Homo Sapiens (Cro-Magnon), who supplanted Neanderthal man.
In the Neolithic period, there is a correlation between the Holocene thermal maximum and human technological development. It is more than likely that technological development was spurred by a concatenation of conditions that included a milder climate. The resulting improvement in living conditions and capacity to produce food, naturally caused a decline in infant mortality, thereby driving demographic growth.
The modern era covers the last 10 000 years. In what is sometimes called the Neolithic revolution, man started to imitate nature by sowing seeds. He domesticated animals, stopped wandering, and settled. He could now devote more time than before to provide for his ever-growing needs. What previously were feuds became wars, aided and abetted by the invention of metal weapons. The settling process led to the emergence of civilization, which also marked the onset of human struggles.
This is an important point in our analysis: if humans had never advanced beyond stone tools, we would no doubt still be gatherings of tribes living around waterways. The discovery of metals enabled the transition from stone and wood to metal tools, which were far more effective.
There are three stages in the history of metallurgy.
Each step constituted an advance in tool making. In the final step, steel was used to manufacture machines to handle the tools in place of humans, laying the foundations for the industrial civilization.
The other side of the coin was the production of increasingly sophisticated weapons.
In the early centuries of the second millennium, when the West was still building strongholds that consisted of mounds surrounded by palisades, the Crusades started to bring the West the wealth and knowledge that would foster the development of this part of the world and set the conditions for subsequent events.
By the 15th century, out of the great civilizations with metallurgical skills – China, Japan, the Middle East, Africa and the West – only China and the West had mastered ocean navigation.
The Chinese emperor Yongle sent 70 ships and 30 000 men to the South Seas. The emperor Hongxi put an end to this adventure, however, nipping China’s colonial expansion in the bud. The road was now open for the West to conquer the world – which it did in the 16th century, reaping the “New World” as its prize. The scale of the wealth that poured into the West was immeasurable, enabling the West to deepen its knowledge in all areas, raise armies, and lay claim to the resources of the planet. The surplus wealth enabled a growing share of the population to acquire the knowledge of the time and delve further. The progress of knowledge was exponential. Techniques evolved, and the more they advanced, the more accessible natural resources became. These were already immeasurable; they became infinite.
At the same time, part of the population settled in North America, exploited the abundant and diversified local natural resources and founded a nation. The combination of such resources and the new nation’s special relationship with Europe, where the knowledge of the time was concentrated, created the world’s richest and most powerful state. It was not at all a matter of intelligence, just a question of accessible resources.