The Anthropocene as the age of human expansionism

Human systems

• For human systems, the Anthropocene is the story of a lightning evolution.

• This evolution, which has been taking place for several centuries but especially since the end of the Second World War, is referred to as the "Great Acceleration".

• It corresponds to an unprecedented increase in the population and in the production of goods and services, as measured by the Gross Domestic Product (GDP).

• In two centuries, the number of humans has been multiplied by 8 [1], world GDP by 90 and GDP per capita by more than 10 [2].

• In 2020, we have reached a symbolic threshold where the mass of what humans make weighs more than the entire mass of living things [3].

• Plastic is an emblematic example of the producer-consumer society. The total amount of plastic produced since 1950 reaches nearly 10 billion tons, and more and more plastic is produced each year [4].

• The "Great Acceleration" has very strong effects at human level: during the whole history of humanity, never individuals have lived so long, eaten so much, been so educated and possessed so many material goods as today, despite irrational inequalities [5, 6, 7, 8, 9].

• This incredible growth goes hand in hand with an extremely strong rise in energy consumption, particularly from fossil fuels. Between 1800 and 2020, energy consumption has multiplied by 30 [10].

• Between 1950 and 2020, the consumption of coal increased by 3, that of oil by 9 and that of gas by 18 [10]!

• The burning of fossil fuels generates in return the emission of greenhouse gases and so changes the composition of the atmosphere. Every year, human activity emits nearly 40 billion tons of CO2 into the atmosphere, nearly 10 billion tons of methane and a few billion tons of nitrous oxide [11].

Key messages

For a very long time, the human population varied between a few million and a few hundred million inhabitants. Between 1800 and 2020, it was multiplied by 8 to finally exceed 8 billion inhabitants in 2022 [1]! This brutal increase is unprecedented in the whole history of humanity. On the long time scale (left graph), the increase seems instantaneous! In a shorter perspective (right graph), we note a significant increase in the population from about 1700, a stronger increase from about 1850 and a lightning acceleration at the end of the Second World War (the Great Acceleration ). Source of data: Our World In Data [1].

The time of an unprecented rise in global population

Like human population, GDP has known a lightning evolution during the last decades. Between 1800 and 2020, it has been multiplied by 90 [2]! On the long time scale (left graph), the increase seems instantaneous and overwrites all previous variations! In a shorter perspective (right graph), we note a significant increase in world GDP from around 1850 and a lightning acceleration at the end of the Second World War. Source of data: Our World In Data [2].

A new universal dogma: GDP growth

As the world GDP is increasing much faster than the number of inhabitants, the GDP per capita is also experiencing a striking rise. In two centuries, it has been multiplied by 15 [2]. Once again, the evolution is particularly marked from 1945. Source of data: Our World In Data [2].

By 2020, we would have reached a symbolic point where the mass of what humans produce exceeds the biomass. In other words, what humans produce weighs more than all the life on this planet!

Source of the chart: Elhacham, E. et al., Nature, 2020 [3].

A civilization of producers-consumers

The incredible growth of human activity is linked to the invention and development of increasingly numerous and efficient machines, which in turn depend on abundant and cheap energy (i.e. fossil fuels). The mechanization of agriculture and many industrial sectors has considerably increased a key parameter: productivity.

Productivity is a good way to measure the evolution of human transformative power, as it gives an idea of the quantity of goods and services produced per hour worked. In countries such as France, the United States or the United Kingdom, productivity has multiplied by a factor of 4 to 7 between 1950 and 2020 [2]. In 2020, in 1 hour of work, a French person produces 7 times more goods and services than did its ancestor during the 1950s !

As working time has only slightly decreased, we actually produce many more goods and services than before. Who says increase in production says increase in consumption: on average, never a human has eaten as much and has owned as many material goods as today, even if colossal inequalities remain between individuals.

Plastic production is an emblematic example of the considerable rise in the production of material goods that underpins economic growth.

Before 1950, we did not produce plastic. From the beginning of the 1970s, annual production reached 50 million tonnes per year, then exceeded 100 million tonnes per year at the end of the 1980s (top graph) [4]. In 2019, plastic production exceeded 450 million tons per year!

If we look at the cumulative production of plastic since 1950, we see that it exceeded 9.5 billion tonnes in 2019 (bottom graph) [4]. These plastics largely end up in nature, where they break up into small pieces called micro-plastics. The latter are then easily transported by air or by water and are therefore found anywhere on this planet: at the poles, at the tops of the highest mountains, but also and above all in the ocean.

The plastic waste in the ocean is so important that it has accumulated to form a kind of continent, the plastic vortex, located in the Pacific and whose surface would be 3 times that of metropolitan France.

Source of data: Our World In Data [4].

Source of data : Our World In Data [2].

Humans are living longer, are richer and (too) well nourished

The recent period is characterized by an extraordinary growth in the number of humans or in the quantity of goods and services produced and consumed by each.

However, the changes affected many other aspects as well. The mechanization of processes and the increase in agricultural yields, made possible by the exploitation of fossil resources, have, for example, considerably lowered the labor required for the production of food or various material goods. An increasingly large part of the population could manage other tasks, which contributed to rapid progress in the fields of health or education.

Thus, in addition to a very strong reduction in the proportion of the population living in conditions of extreme poverty [8], spectacular changes are visible, for example, in life expectancy [5], infant mortality [6] or in the level of education of the population [9].

Since 1850, life expectancy has more than doubled (top chart) [5]. Before 1850, humans lived on average less than 30 years. Two centuries later, most humans live beyond 70 years. This spectacular increase is partly due to a considerable fall in infant mortality (middle graph). Before 1850, more than 40% of children died before the age of 5; today, less than 5% of children die before the age of 5 [6].

Growth has been so strong in some aspects that, even at the human level, it turns into more negative effects. For example, caloric intake has become so important that more and more people are concerned by overweight and various associated disorders. At the global level, the share of the overweight population has almost doubled in 40 years (1976-2016) and is now close to 40% (bottom graph) [7]. In the United States, almost 70% of adults are overweight!

It should be noted that these global trends mask incredible inequalities. While some are eating more than they should, famine continues to kill people in some parts of the world. Just as life expectancy, education, infant mortality or poverty have not evolved everywhere in the same way. Infant mortality approaches or even exceeds 10% in some African countries, while it is less than 0.5% in Western European countries [6].

Source of data: Our World In Data [5, 6, 7, 8, 9].

The myth of energy transition versus the reality of energy accumulation

Everyone knows that activity consumes energy. Human activity is no exception to this elementary rule and the unprecedented growth of human activity in recent decades has gone hand in hand with a sharp rise in energy consumption. Between 1800 and 2020, global energy consumption has beenmultiplied by 30: it reached nearly 180,000 terawatt-hours (TWh) in 2022, compared to just under 90,000 TWh in 1980 or 6,000 TWh in 1800 [10].

Fossil fuels have been and still are the driving force of human activity and economic growth. Their advent from around 1850, with first coal and then (late 19th century) oil and gas, is a determining factor in the achievement of economic growth. Between 1950 and 2020, coal consumption increased by 3 (from 13,000 to 42,000 TWh), that of oil by 9 (from 5,000 to 49,000 TWh) and that of gas by 18 (from 2,000 to 39 000 TWh) [10]! Today, fossil fuels still make up around 80% of the energy mix [10].

Energetic transition is a myth: there is no transition to other energy sources, but an addition of more and more diverse energy sources in order to meet the growing energetic needs of a growing human activity.

Solar and wind are barely visible on the graph because of their very low share in the energy mix.

Source of data: Our World In Data [6].

The spectacular developments described above are largely based on the massive use of an extraordinary source of energy: fossil fuels. The use of energy from fossil resources, however, has a very big drawback: it involves their combustion, which generates gaseous waste, including greenhouse gases and in particular CO2.

Since fossil resources were formed millions of years ago, in a process that itself took millions of years, they are non-renewable on the scale of human civilization. Their combustion leads to their final loss and profoundly modifies the carbon cycle, since it realeases into the atmosphere the carbon that had been trapped in the bowels of the Earth for millions of years.

As oil, coal and gas are the bedrock of our civilization, the CO2 emissions related to the combustion of fossil fuels are massive and steadily rising (top graph)! They reach around 35 billion tonnes each year in the early 2020s [11].

The only slight decreases visible on the graph are linked to slowdowns in economic activity: oil shock of 1979, economic crisis of 2008 and covid-19 in 2020 for example.

The CO2 emissions from fossil fuels must be added to the emissions linked to land-use change. For example, when a forest is transformed into agricultural fields, the CO2 stored in the trees and the forest floor is released into the atmosphere, which contributes to CO2 emissions. It is thus estimated that land-use change contributes to the emission of approximately 5 billion tons of CO2 each year [11].

In total, the CO2 emissions related to human activity reach around 40 billion tons (35 billion from the combustion of fossil fuels + 5 billion from land-use change) each year at the start of the 2020s [11]. It is estimated that since 1850, humans have released about 2,500 billion tons of CO2 into the atmosphere [12].

Added to CO2 emissions are emissions of other greenhouse gases, such as methane (CH4; middle graph) or nitrous oxide (N2O; bottom graph), two gases with a warming potential of 30 and 300 times higher than that of CO2. As with CO2, human activity emits more and more methane and nitrous oxide each year.

Source of data: Our World In Data [11].

Growth in human activity means growth in greenhouse gas emissions

References

[1] H. Ritchie et al., « Population Growth », Our World in Data, 2023. https://ourworldindata.org/population-growth

[2] M. Roser, P. Arriagada, J. Hasell, et E. Ortiz-Ospina, « Economic Growth », Our World in Data, 2023. https://ourworldindata.org/economic-growth

[3] E. Elhacham, L. Ben-Uri, J. Grozovski, Y. M. Bar-On, et R. Milo, « Global human-made mass exceeds all living biomass », Nature, p. 1‑3, 2020. https://www.nature.com/articles/s41586-020-3010-5

[4] H. Ritchie et M. Roser, « Plastic Pollution », Our World in Data, 2018. https://ourworldindata.org/plastic-pollution

[5] M. Roser, E. Ortiz-Ospina, et H. Ritchie, « Life Expectancy », Our World in Data, 2019. https://ourworldindata.org/life-expectancy

[6] M. Roser, H. Ritchie et B. Dadonaite, « Child and infant Mortality », Our World in Data, 2019. https://ourworldindata.org/child-mortality

[7] H. Ritchie et M. Roser, « Obesity », Our World in Data, 2017. https://ourworldindata.org/obesity

[8] J. Hasell, M. Roser, E. Ortiz-Ospina, et P. Arriagada, « Poverty », Our World in Data, 2023. https://ourworldindata.org/poverty

[9] M. Roser et E. Ortiz-Ospina, « Global Education », Our World in Data, 2016. https://ourworldindata.org/global-education

[10] H. Ritchie, M. Roser, et P. Rosado, « Energy », Our World in Data, 2022. https://ourworldindata.org/energy

[11] H. Ritchie, M. Roser, et P. Rosado, « CO₂ and Greenhouse Gas Emissions », Our World in Data, 2020. https://ourworldindata.org/co2-and-greenhouse-gas-emissions

[12] S. Evans, « Analysis: Which countries are historically responsible for climate change? », Carbon Brief, 2021. https://www.carbonbrief.org/analysis-which-countries-are-historically-responsible-for-climate-change/