According to a study at the Weizmann Institute of Science in Israel, the world’s 7.6 billion people represent just 0.01% of all living things.
In this groundbreaking assessment, we see what humanity is really doing to life on this planet in a way we never have before. The study reveals that from the beginning of human civilization we have caused the loss of 83% of all wild mammals and half of plants. All that while “livestock” has taken over.
This is the first far-reaching estimate of all living things and what impact they all have both in population and direct actions. Bacteria are 13% of everything while plants are the major life form on our planet making up 82% of all living matter. All other creatures like fish, fungi, and insects make up only 5% of the world’s biomass.
Another big surprise of the study was that the ocean that is packed with life and covering most of the planet’s surface is just 1% of all biomass. Most life is land-based and an eight of that is bacteria living far under the earth’s surface.
“I was shocked to find there wasn’t already a comprehensive, holistic estimate of all the different components of biomass,” said Prof Ron Milo, at the Weizmann Institute of Science in Israel, who led the work, published in the Proceedings of the National Academy of Sciences.
“I would hope this gives people a perspective on the very dominant role that humanity now plays on Earth,” he said, adding that he now chooses to eat less meat due to the huge environmental impact of livestock.
Humanity has transformed the face of the earth so drastically that scientists declared a new geological era called the Anthropocene. Scientists have even suggested that we use the bones of domestic chickens as the marker for this new geologic era as we have bred them en mass across the planet for centuries.
In fact, 70% of all birds on the planet are now “poultry” raised for human consumption with just 30% of all birds being wild according to the study.
Alarmingly the same study also shows that 60% of all mammals on Earth are now “livestock” mostly composed of pigs and cattle. Just 4% are wild animals with humans making up 36% of mammals.
“It is pretty staggering,” said Milo. “In wildlife films, we see flocks of birds, of every kind, in vast amounts, and then when we did the analysis we found there are [far] more domesticated birds.”
All of the logging, land development, and farming as created the sixth mass extinction of life on the planet. Humans are responsible for the newest mass extinction event in all of the Earth’s four billion year history. Nearly half of all animals have been lost in just the last 50 years alone.
Comparing these new estimates from the study with those before humanity settled down into an industrial society shows the truly massive and horrific decline we’ve caused. Only one-sixth of wild mammals still exist which was shocking even to the scientists.
Looking back towards the Earth’s oceans three centuries of unregulated whaling has dwindled marine mammal populations down to just a fifth of what it once was.
“It is definitely striking, our disproportionate place on Earth,” said Milo. “When I do a puzzle with my daughters, there is usually an elephant next to a giraffe next to a rhino. But if I was trying to give them a more realistic sense of the world, it would be a cow next to a cow next to a cow and then a chicken.”
Milo places specific emphasis on diet being a primary driver of the impact we’ve had on animals and the planet:
“Our dietary choices have a vast effect on the habitats of animals, plants and other organisms.”
“I would hope people would take this [work] as part of their world view of how they consume,” he said. ”I have not become vegetarian, but I do take the environmental impact into my decision making, so it helps me think, do I want to choose beef or poultry or use tofu instead?”
Using hundreds of studies the scientists collated everything into the calculated biomass estimate using modern techniques like satellite remote sensing and gene sequencing.
Paul Falkowski, at Rutgers University in the US and not part of the research team, said:
“The study is, to my knowledge, the first comprehensive analysis of the biomass distribution of all organisms including viruses on Earth.”
“There are two major takeaways from this paper,” he said. “First, humans are extremely efficient in exploiting natural resources. Humans have culled, and in some cases eradicated, wild mammals for food or pleasure in virtually all continents. Second, the biomass of terrestrial plants overwhelmingly dominates on a global scale – and most of that biomass is in the form of wood.”