Scientists at the Weizmann Institute of Science compare the mass of the living with the one of the human-made, where humans have become the dominant forces shaping the surface of the planet
Global Human-Made Mass Exceeds All Living Biomass
According to the research made by Israel’s Weizmann Institute of Science Department of Plant and Environmental Sciences in 2020, the total mass of all human-made objects now exceeds the mass of all living things on Earth.
In the startling study made by Scientist Ron Milo of the Weizmann Institute and colleagues, the year 2020 marked a crossover point, where the anthropogenic mass, in other words the mass of human-made objects, began outweighing the global (dry) biomass which today, approximately equals to 1.1 tera tons (Tt).
The research, which was published in the Nature Journal, explains that on average, each person produces more anthropogenic mass per week compared to his or her bodyweight. The study on the evolution of material input, presents quantifiable evidence on the weight of humanity’s footprint, displaying the deeper layers of dominance over nature.
Lampoon – Scientist Ron Milo of the Weizmann Institute
«It gives a scientific and intuitive way to understand that we are in a special time in history, that our effect becomes real on a planetary scale and gives us a tool in order to discuss it with others. If somebody is skeptical about how much our actions matter, it gives us one example of the fact that we are in a situation where we should think about our actions». explains Prof. Milo.
Starting from 1900 till present day, the paper calculates and compares the mass of the living vs. the mass of human-made, providing a quantified and symbolic depiction of the new geological epoch, the Anthropocene.
The calculations on the global biomass
According to Prof. Ron Milo, the idea to compare the mass of the living with the mass of the human-made began with completely different research which aimed to discover the most abundant enzyme on the planet, in order to assist a process called carbon fixation.
The study required Prof. Milo and his graduate student Yinon Bar-On to collect data on the mass of all living things, «in order to analyze it properly, we need to know the mass of all sorts of groups of living things. I initially thought that it was going to be an easy task but it turned out to be the complete opposite and it became a journey which lasted 3 years. We forgot about the original question in the end», Prof. Milo explains.
Once the calculations on the global biomass were finished, «I don’t remember when and how, but the question arose in my mind, how does that compare to the mass of human-made things? There is so much around us that is made by humans».
Defining Anthropogenic Mass and Global Biomass
Over the past 100 years, while the global biomass stayed more or less the same, the anthropogenic mass has accelerated in great numbers. The research reveals, at the beginning of the 20th century, anthropogenic mass was equivalent to 3% of global biomass. As enhanced consumption and urban development increased, the gap between the two rapidly shrunk.
From buildings to infrastructure to telephones, the study defines anthropogenic mass as «the mass embedded in inanimate solid objects made by humans that have not been demolished or taken out of service, which does not include waste».
The main subgroups that define anthropogenic mass (from the greatest mass to the least) include; concrete, aggregates, bricks, asphalt, metals, glass and plastic, compromising mainly of materials used in infrastructure, buildings and everyday objects.
On the other hand, the study divides global biomass into two groups. The global dry biomass represents the mass of all living organisms, excluding water, while the global wet biomass includes the mass of water within the calculations. As for the organisms which constitute the global biomass, they are made up mainly of plants, followed by bacteria, fungi, archaea, protists and animals.
Humans Present 0.01% of Global Biomass
Today, the population of humans nears 8 billion and in terms of mass, presents only 0.01% of the current global biomass. Plants on the other hand make up 90% of the global biomass which equals approximately 900 Gt (gigatonnes).
From the first agricultural revolution till present day, humanity has reduced the mass of plants from 2 Tt to approximately 900 Gt. The main trend which poses the greatest risk to the global biomass comes from modern agriculture’s increasing utilization of land, as well as deforestation, poor forest management, overfishing, hunting, animal husbandry and employment of land for other purposes.
«It gives us a way to recognize the situation currently on Earth or as some people would say, we are only one species out of many therefore, how much effect could we have on the planet Earth? This enables you to go in a scientific way and compare our effect and you find that even though we are just one specifies, 8 billion of us have quite a tremendous effect in shaping what is on the Earth. With that also comes some responsibility. Because when you understand that you are a significant player, that brings more thought on how do you take care of the Earth».
Plastic alone is greater in mass than all land animals and maritime animals combined
«Plastic captures our attention, in a very strong way, more than its fraction out of the mass and that’s for several reasons. One of the reasons is the fact that it is very resistant and also tends to float. If you throw a lot of cement in the ocean, it just sinks and you won’t see it. But if you throw plastic, you will see it. This is also true if you throw it in your backyard, cement would stay there, but plastic starts to disperse, it starts to move with the currents, the wind and therefore you see it much more. With the effect of the plastic, it relates less to how much mass there is, but really how much we see it. How much we are offended by it and the visual burden it creates for us».
Anthropogenic Mass Will Triple Global Biomass in 2040
Another revelation comes in the form of changes in humanity’s material output, which is directly tied to global events, such as economic crises, world wars, conflicts etc. Based on the records, the biggest shifts in anthropogenic mass occurred after World War II, due to enhanced consumption and urban development, also defined as the period of Great Acceleration.
During the mid-1950s, urban consumption became compromised more in favor of concrete rather than brick, which in the following decades became the dominant material for urbanization, acting as the foundation for modern development and infrastructure, as well as a dividing force between humans and nature. Though concrete is preferred for its endurance, humanity’s dependence on the material has placed itself, after water, as the most widely used substance on Earth.
2040 anthropogenic mass will triple in mass compared to the global dry biomass
A similar story can be told for asphalt as well. In the 1960s, as the construction for urbanized cities gained momentum, asphalt became one of the defining materials for infrastructure and modernization, emerging as a major road and pavement material. These everyday materials have become the defining ingredients for urbanization and development. However, their impact on the natural biomass has come with substantial consequences, as vast tracks of fertile soils are choked, habitats are divided and the climate is disrupted.
The study claims, if the accumulation of these objects continues, in the year 2040 anthropogenic mass will surpass 3 Tt, tripling in mass compared to the global (dry) biomass. Though the calculations of the research draw a rather gloomy picture of the future, Prof. Milo believes that it is a matter of balance, a division where the concentration of anthropogenic mass should stay within the cities, separate from natural life and that humanity must focus efforts on science to bring forward effective solutions.
The Anthropocene
Humanity’s ability to transform geological materials into useful forms has affected natural habitats, biodiversity and various climatic and biogeochemical cycles. Hence, the research supports the idea that our current epoch should be named Anthropocene, in order to understand and accept humans as the main force changing the planet’s geology.
«In order to grasp many of the environmental challenges we are facing, we need to realize the situation we are in and the Anthropocene conveys that message. That we are in a new geological era, in a new period starting with humans. I think that conveys it within the name».
Professor Ron Milo
Ron Milo is a professor at the Weizmann Institute of Science in the Department of Plant and Environmental Sciences in Rehovot, Israel. His study, Global human-made mass exceeds all living biomass was published in the Nature Journal in 2020. He is also the author of Cell Biology by the Numbers which was published in 2015.
