In this April 11, 2018, file photo, two boys push their scooters through a park with green blossoming trees in Frankfurt, Germany. When you weigh all life on Earth, billions of humans don't amount to much compared to trees, earthworms or even viruses, according to a study in the Monday, May 21, 2018, Proceedings of the National Academy of Sciences. (AP Photo/Michael Probst, File) When you weigh all life on Earth, billions of humans don't amount to much compared to trees, earthworms or even viruses. But we really know how to throw what little weight we have around, according to a first-of-its-kind global census of the footprint of life on the planet. 
 
 Humans only add up to about one ten-thousandth of the life on Earth, measured by the dry weight of the carbon that makes up the structure of all living things, also known as biomass. 
 
 The planet's real heavyweights are plants. They outweigh people by about 7,500 to 1, and make up more than 80 percent of the world's biomass, a study in Monday's Proceedings of the National Academy of Sciences said. 
 
 Bacteria are nearly 13 percent of the world's biomass. Fungi—yeast, mold and mushrooms—make up about 2 percent. These estimates aren't very exact, the real numbers could be more or less, but they give a sense of proportion, said study lead author Ron Milo, a biologist at the Weizmann Institute of Science in Israel. 
 
 "The fact that the biomass of fungi exceeds that of all animals sort of puts us in our place," said Harvard evolutionary biology professor James Hanken, who wasn't part of the study. 
 
 Still, humans have an outsized influence on its more massive fellow creatures. Since civilization started, humans helped cut the total weight of plants by half and wild mammals by 85 percent, the study said. 
 
 In this Sept. 22, 2017, file photo, John Locke works to move a herd to another field at his family's ranch in Glen Flora, Texas. Now domesticated cattle and pigs outweigh all wild mammals by 14 to 1, while the world's chickens triple the weight of all the wild birds, according to a study in the Monday, May 21, 2018, Proceedings of the National Academy of Sciences. (AP Photo/Eric Gay, File) 
 
 Now domesticated cattle and pigs outweigh all wild mammals by 14 to 1, while the world's chickens are triple the weight of all the wild birds. Instead of children's books about elephants and lions, a more honest representation of Earth's animals would be "a cow next to another cow, next to another cow next to a chicken," Milo said. 
 
 Milo and colleagues took earlier research that looked at biomass for different types of life, combined them, factored in climate, geography and other environmental issues, to come up with a planetwide look at the scale of life on the planet. Taking water out of the equation and measuring only dry carbon makes it easier for scientists to compare species. About one-sixth the weight of a human is dry carbon. Humans are about two-thirds water. 
 
 "Even though short in numbers, we have managed to throw a lot of sand in the air and mess up a lot of things," said noted Harvard biologist E.O. Wilson, who wasn't involved in the study. 
 
 Explore further: Humans may influence cancer in many other species on the planet 
 
 More information: Yinon M. Bar-On el al., "The biomass distribution on Earth," PNAS (2018). www.pnas.org/cgi/doi/10.1073/pnas.1711842115 ||||| Groundbreaking assessment of all life on Earth reveals humanity’s surprisingly tiny part in it as well as our disproportionate impact 
 
 Humankind is revealed as simultaneously insignificant and utterly dominant in the grand scheme of life on Earth by a groundbreaking new assessment of all life on the planet. 
 
 The world’s 7.6 billion people represent just 0.01% of all living things, according to the study. Yet since the dawn of civilisation, humanity has caused the loss of 83% of all wild mammals and half of plants, while livestock kept by humans abounds. 
 
 The new work is the first comprehensive estimate of the weight of every class of living creature and overturns some long-held assumptions. Bacteria are indeed a major life form – 13% of everything – but plants overshadow everything, representing 82% of all living matter. All other creatures, from insects to fungi, to fish and animals, make up just 5% of the world’s biomass. 
 
 Another surprise is that the teeming life revealed in the oceans by the recent BBC television series Blue Planet II turns out to represent just 1% of all biomass. The vast majority of life is land-based and a large chunk – an eighth – is bacteria buried deep below the 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. 
 
 The transformation of the planet by human activity has led scientists to the brink of declaring a new geological era – the Anthropocene. One suggested marker for this change are the bones of the domestic chicken, now ubiquitous across the globe. 
 
 The new work reveals that farmed poultry today makes up 70% of all birds on the planet, with just 30% being wild. The picture is even more stark for mammals – 60% of all mammals on Earth are livestock, mostly cattle and pigs, 36% are human and just 4% are wild animals. 
 
 “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.” 
 
 The destruction of wild habitat for farming, logging and development has resulted in the start of what many scientists consider the sixth mass extinction of life to occur in the Earth’s four billion year history. About half the Earth’s animals are thought to have been lost in the last 50 years. 
 
 
 
 But comparison of the new estimates with those for the time before humans became farmers and the industrial revolution began reveal the full extent of the huge decline. Just one-sixth of wild mammals, from mice to elephants, remain, surprising even the scientists. In the oceans, three centuries of whaling has left just a fifth of marine mammals in the oceans. 
 
 “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.” 
 
 Despite humanity’s supremacy, in weight terms Homo sapiens is puny. Viruses alone have a combined weight three times that of humans, as do worms. Fish are 12 times greater than people and fungi 200 times as large. 
 
 But our impact on the natural world remains immense, said Milo, particularly in what we choose to eat: “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?” 
 
 The researchers calculated the biomass estimates using data from hundreds of studies, which often used modern techniques, such as satellite remote sensing that can scan great areas, and gene sequencing that can unravel the myriad organisms in the microscopic world. 
 
 They started by assessing the biomass of a class of organisms and then they determined which environments such life could live in across the world to create a global total. They used carbon as the key measure and found all life contains 550bn tonnes of the element. The researchers acknowledge that substantial uncertainties remain in particular estimates, especially for bacteria deep underground, but say the work presents a useful overview. 
 
 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.” ||||| Plants outweigh all other life on Earth 
 
 Plants pack more heft than any other kingdom of life on the planet, making up 80% of all the carbon stored in living creatures. That’s just one surprise in a comprehensive new survey of Earth’s biomass, which finds that groups with the greatest number of species—such as arthropods—aren’t necessarily the heaviest. 
 
 version="1.0" encoding="utf-8"? Archaea Viruses Bacteria Protists Fungi Animals Arthropods Molluscs Nematodes Annelids Wild birds Fish Wild Humans Livestock Cnidarians Kingdoms of life Animals Plants 450 GT C 0.1 0.1 0.06 mammals 0.007 0.7 0.002 0.2 0.02 0.2 1 GT C 2 12 4 70 0.2 8 
 
 Measured in terms of carbon content (to factor out variable components like water), all life on Earth weighs about 550 gigatons. Of that, plants make up 450 gigatons of carbon (GT C), followed by bacteria at 70 GT C and fungi at 12 GT C, scientists report today in the Proceedings of the National Academy of Sciences . Animals comprise a mere 2 GT C, of which half are arthropods—including insects, spiders, and crustaceans. And although humans weigh in at just 0.06 GT C—on par with krill and termites—our impact on biomass since the beginning of civilization has been huge, scientists say. Humans and their cattle, pigs, and other livestock outweigh wild mammals by more than 20-fold; similarly, domesticated fowl surpass all other birds. Humans have also had an impact on plant biomass, which has been cut in half in the past 10,000 years. 
 
 To figure out the biomass of each creature, quantitative biologists spent 3 years combing the scientific literature. But their ultimate goal wasn’t to figure out how much life weighs—it was to discover the most abundant protein on the planet. They’re still working on that question (subsurface microbes presented them with a particular challenge), but they hope to answer it within the coming year.
– A first-of-its-kind study reveals that humans make up a minuscule portion of life on the planet. As in 0.01%, reports the Guardian. The flip side of that? Despite the scant figure, humans have reshaped the animal kingdom, helping wipe out about 83% of mammals and half of all plants since civilization began, according to the comprehensive survey in the Proceedings of the National Academy of Sciences. For this study, researchers weren't counting individual members of species. This is all about weight—they surveyed the Earth's biomass, meaning the carbon content in living creatures. Start with this: All life on the planet weighs about 550 gigatons, notes Science. The new study breaks down that figure, including these highlights: Plants account for an astounding 82% of the planet's biomass Bacteria make up 13%—leaving just 5% for everything else beyond plants and bacteria Fungi (think yeast, mold, and mushrooms) make up 2% Ocean life makes up a surprisingly small 1% Chicken and other poultry make up 70% of all birds on the planet; only 30% are wild Livestock (mostly cows and pigs) make up 60% of all mammals; humans account for 36% of mammals, leaving only 4% as wild "The fact that the biomass of fungi exceeds that of all animals sort of puts us in our place," says Harvard biology professor James Hanken, who wasn't part of the study, per a release at Phys.org.