Human Race Just 0.01% of All Life But Has Destroyed 83% of Wild Mammals, Study Finds (theguardian.com)

An assessment of all life on Earth has revealed humanity's surprisingly tiny part in it as well as our disproportionate impact. From a report: 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.

Comments

Re:I kill a moose a year to feed my family.

[Oligonicella]

How much of that Moose do you use to feed your family.(?)

If it's like with deer around here, almost all of it. Steaks, burger and sausage. Bones and offal for the dogs. Hide sold for leather and antlers have various uses. Not much left.

Don't project your cultural norms onto others.

Re:humans have 2 legs. dogs have 5 million follicl

[dinfinity]

0.01% of life by weight is currently humans, but we've killed 83% of mammal species... by species count? individuals?

Individuals. RTFA.

what percentage of mammal species does humanity account for? by weight or by head count?

36%, by head count. RTFA.

what about other groups? insects? viruses? reptiles?

They 'measured' marine mammals (80%), plants (50%), fish (15%). RTFA.

Get your shit together, AC. Get it all together and put it in a backpack.

Obligatory XKCD

[Paul Fernhout]

Earth's Land Mammals by Weight: https://xkcd.com/1338/

Explained: https://www.explainxkcd.com/wi...

It references a 2002 book: "The Earth's Biosphere: Evolution, Dynamics, and Change".

So, while this topic is very important, I'm not sure what in the study is actually "news"? Maybe the low percentage of ocean biomass (which I feel is hard to believe)?

Re:humans have 2 legs. dogs have 5 million follicl

[careysub]

0.01% of life by weight is currently humans, but we've killed 83% of mammal species... by species count? individuals?

Individuals. RTFA.

Says a guy who didn't read the actual paper and is guessing?

That percentage was calculated from this line in the actual (not made-up) report:

The Report:
"Human activity contributed to the Quaternary Megafauna Extinction between 50,000 and 3,000 y ago, which claimed around half of the large (>40 kg) land mammal species (30). The biomass of wild land mammals before this period of extinction was estimated by Barnosky (30) at 0.02 Gt C. The present-day biomass of wild land mammals is approximately sevenfold lower, at 0.003 Gt C."

100*(1 - 0.003/0.02) = 85%, not exactly the 83% quoted but within the accuracy of the estimate.

what percentage of mammal species does humanity account for? by weight or by head count?

36%, by head count. RTFA.

The paper is entirely done with biomass estimates. Why are you BSing everyone?