Humanity is a completely insignificant part of a large set of life on Earth, but at the same time it is completely dominant. It showed a new pioneering assessment of all life existing on our planet.
According to this study, 7.6 billion people in the world make up only 0.01 % (yes, only a hundredth of a percent) of all living beings. Nevertheless, since the beginning of civilization, mankind has caused the loss of 83 % of all wild mammals and half of the plants, while the population of livestock kept for human consumption is constantly growing.
Recently, a new work has been published, which is the first comprehensive estimate of the mass of each class of living creatures and refutes some of the long-standing assumptions. Bacteria are really the main form of life on Earth - they make up 13 % of everything, but everything overshadows plants, because they represent 82 % of all living matter. All other creatures, from insects to fungi and fish to animals, make up only 5 %s of global biomass.
Another big surprise is that life flourished in the oceans, which was revealed by the BBC's new television series "Blue Planet II“, Makes up only about 1 % of all biomass. The vast majority of life is terrestrial, and much of it - the eighth largest - is made up of bacteria living deep underground.
"I was very surprised to find that there is no comprehensive estimate of all the different components of biomass," said prof. Ron Milo of the Weizmann Institute of Science in Israel.
"I hope that people will realize the reality of the very dominant role that humanity is now playing on Earth," he said, adding that he had decided to eat less meat due to the huge negative impact of livestock farming on the environment.
The transformation of the planet due to human activity has brought scientists to the brink of declaring a new geological era - the anthropocene. One piece of evidence for this change is the domestic chickens that are present around the world today.
The new work reveals that farmed poultry today make up 70 % of all birds on the planet, while wild birds make up only 30 %. The image is much rougher in mammals - 60 % mammals on Earth are farm animals, mostly cattle and pigs, 36 % are humans and only 4% wild animals.
"The data is quite astounding," Milo said. "In wildlife movies, we see flocks of birds of all kinds in huge numbers, but when we did the analysis, we found that many more birds lived in artificial farms."
The destruction of wildlife due to agriculture, logging and development led to the beginning of what many scientists consider to be the sixth mass extinction of life that occurred during the four billion years of Earth's history. In the last 50 years, about half of the Earth's animals have probably become extinct.
A comparison of the new estimates with the data for the period before humans began agriculture and the industrial revolution broke out showed the full extent of the huge decline. Only one-sixth of wild mammals, from mice to elephants, survived, surprising even the scientists themselves. Only one-fifth of marine mammals have survived whaling in the oceans in three centuries.
"Our disproportionate place on Earth is definitely visible," Milo said. "When I play with my daughters and put together puzzles, next to the giraffe there is usually an elephant and a rhino standing next to it. But if I wanted to show them a more realistic world, it would be a cow next to a cow next to a cow and then a chicken. "
Despite the superiority of Homo sapiens, the greatness of humanity expressed in weight is insignificant. The viruses themselves weigh three times as much as humans, just like earthworms. Fish are 12 times heavier than humans and mushrooms even 200 times.
"But our impact on the natural environment remains enormous," Milo said, especially from what we choose to eat: "Our eating habits have a huge impact on the environment of animals, plants and other organisms, including our own."
"I hope people take this job as part of looking at the impacts of their lifestyles," he said. "Although I did not become a vegetarian, I take into account the impact of my choice on the environment when making my decisions. That allows me to choose whether to have beef, poultry or tofu. ”
Researchers have calculated biomass estimates using data from hundreds of studies conducted using modern technologies such as satellite remote sensing, which can scan large areas, and gene sequencing, which can recognize countless organisms in the microscopic world.
They began by evaluating the biomass of a particular class of organisms and then determined the environment in which such life could exist in the world. They then created a global summary. They used carbon as a key element and found that all life contains 550 billion tons of this element. Researchers are, of course, aware that specific estimates may not be 100%, especially for bacteria deep underground. However, he claims that the work provides a very useful holistic overview.
Paul Falkowski, who works at Rutgers University in the United States and is not part of the research team, said: "In my opinion, the study is the first comprehensive analysis of the biomass distribution of all organisms - including viruses - on Earth."
"Two fundamental conclusions emerge from this article," he said. "First, humans are extremely efficient at using natural resources and have almost, in some cases completely, exterminated wild mammals for food or pleasure on virtually all continents. Secondly, terrestrial plant biomass predominates worldwide - and most of the biomass is in the form of wood. "
(Source: The Guardian)
Ecological definition of biomassIn ecology, biomass is a term defined as the sum of the masses of individuals of a particular species, group of species, or all species of a community. The total is the sum of this group on the given area. The state of the organisms can be distinguished with regard to the possibilities of technical use. In plants, underground or above-ground biomass, dry or vegetative biomass are distinguished in this way.