For much of history, human life was tragically short. It’s estimated that for the vast majority of our existence, life expectancy at birth hovered around a mere 10 years. To illustrate this stark reality, consider Iron Age France (800 B.C.E. to about 100 C.E.), where the average life expectancy was a mere 10 to 12 years. In such conditions, a staggering birth rate of approximately 80 live births per 1,000 people would have been necessary just to sustain the human species. Compare this to today’s world, where a high birth rate, observed in some sub-Saharan African nations, ranges from about 35 to 45 live births per 1,000 population.
These drastically short lifespans meant that for millennia, the human population struggled to grow. Estimates for the Roman Empire in 14 C.E., stretching from Spain to Asia Minor, place the population at around 45 million. However, some historians propose figures twice as high, highlighting the inherent uncertainty in population estimates from early historical periods. Understanding these figures helps contextualize just how long humans have been around and the slow pace of population growth for much of that time.
By 1650, the global population had only reached approximately 500 million – a modest increase from the estimated 300 million in 1 C.E. The average annual growth rate during this period was actually lower than the rate suggested for the era between 8000 B.C.E. and 1 C.E. A significant factor in this slow growth was the Black Death. This devastating plague, infamous for its impact on 14th-century Europe, may have originated in western Asia around 542 C.E. and subsequently spread. Experts believe that the plague decimated half of the Byzantine Empire in the sixth century, resulting in an estimated 100 million deaths. These massive population fluctuations over extended periods significantly complicate the task of accurately estimating the total number of humans who have ever lived.
However, starting around 1800, a dramatic shift occurred. The world population surpassed the 1 billion mark and has since experienced exponential growth, reaching its current estimate of 8 billion in 2022. This unprecedented growth is largely attributed to advancements in public health, medicine, and nutrition. These advancements have dramatically lowered death rates, enabling more individuals to live well into their reproductive years and beyond. This rapid expansion in recent centuries provides a stark contrast to the slow growth that characterized most of how long humans have been around.
Estimating Human Population History: Assumptions and Calculations
Attempting to estimate the total number of people ever born requires us to determine population sizes at various points throughout human prehistory and history. This process also necessitates applying assumed birth rates to each distinct period. For simplicity, let’s start at the very beginning – with a hypothetical initial pair of humans. While the descent of humanity from just two individuals is unlikely, this minimalist approach helps simplify our estimations when considering how long humans have been around.
One complex variable is the pattern of population growth itself. Did the population rise to a certain level and then fluctuate wildly due to factors like famines and climate changes? Or did it grow at a more consistent rate? While definitive answers remain elusive, paleontologists have proposed various theories. For the purpose of estimation, assuming a constant growth rate for each period leading up to modern times provides a workable model. For birth rates, we can assume 80 births per 1,000 people annually up to 1 C.E., and 60 per 1,000 from 2 C.E. to 1750. Subsequently, birth rates declined to below 20 per 1,000 in the modern era.
Utilizing this semi-scientific methodology yields an estimated total of approximately 117 billion births since the emergence of modern humans. The period from 190,000 B.C.E. to 1 C.E. is particularly crucial to this estimate, yet unfortunately, our knowledge of population size during this vast era remains limited. If there’s a potential flaw in this calculation, it might be that our method slightly underestimates the number of births. The assumption of constant population growth in the earlier periods, rather than a more fluctuating pattern, could lead to an underestimation of the average population size during those times. Despite these uncertainties, this estimation provides valuable insight into how long humans have been around and the scale of human history.
The Significance of Today’s Population
Considering the current global population of approximately 8 billion, the estimated 117 billion total births suggests a remarkable conclusion: those alive in 2022 represent nearly 7% of all humans who have ever lived. Given that modern humans have existed on Earth for roughly 200,000 years, this percentage is surprisingly substantial. It underscores the relatively recent explosion in human population compared to the vast expanse of how long humans have been around.
TABLE 2. Snapshot of Population History
| Estimated number of people ever born | 117,020,448,575 |
|---|---|
| World population in mid-2022 | 7,963,000,000 |
| Percentage of those ever born who are living in 2022 | 6.8 |
As archaeological discoveries continue to be made and analyzed with increasingly advanced techniques, our understanding of human population history will undoubtedly expand. This ongoing research will refine our estimations and provide even more intriguing perspectives on the long and complex journey of human existence and how long humans have been around on planet Earth.
