Human-made materials now outweigh Earth's entire biomass: study

A research reported by The Guardian revealed that human-made materials outweighed the overall living biomass on Earth today.

The study, carried out by researchers to provide an objective measure of the reality of the balance between man and nature, estimated that the amount of plastic alone is greater in mass than all land animals and marine creatures combined.

Human activity including the production of concrete, metal, plastic, bricks and asphalt outweighs the overall living biomass on Earth, the study concluded.

A paper published in Nature stated that on average, each week, every person is responsible for the creation of human-made matter equal to more than their own bodyweight.

The researchers are supporting a proposal to name the current epoch as 'Anthropocene,' reflecting the abrupt and considerable impact of human activity.

Ron Milo and his colleagues at the Weizmann Institute of Science in Rehovot studied the change in global biomass and human-made mass from 1900 to present day. They analysed human-made mass in the form of buildings and infrastructure, composed of concrete, aggregates, bricks and asphalt.

The study found that at the start of the 20th century, the mass of human-produced objects was equivalent to nearly three per cent of the world's total biomass. Whereas, in 2020, human-made mass jumped to about 1.1 teratonnes, exceeding overall global biomass.

The increase in human-made mass has impacted plant biomass. “Since the first agricultural revolution, humanity has roughly halved the mass of plants,” the authors said. “While modern agriculture utilises an increasing land area for growing crops, the total mass of domesticated crops is vastly outweighed by the loss of plant mass resulting from deforestation, forest management and other land-use changes. These trends in global biomass have affected the carbon cycle and human health,” they added.

According to the authors, shifts in total anthropogenic mass are tied to global events such as world wars and major economic crises.

Following the second world war, there were continuous increases in human-made mass of more than five per cent per year. This period, known as the "great acceleration" was characterised by enhanced consumption and urban development.

The weight of the human footprint decreases during times of downturn, such as the Great Depression and the 1979 oil crash.

“The face of Earth in the 21st century is affected in an unprecedented manner by the activities of humanity and the production and accumulation of human-made objects,” researchers said.

Since the 1900s, the overall biomass has slightly reduced. Meanwhile, human-made mass has increased rapidly to a production rate of over 30 gigatonnes (30,000,000,000 tonnes) per year. By this rate, the weight of our impact will exceed 3 teratonnes by 2040.