A group of scientists have written a paper for the U.S. National Academy of Sciences estimating the weight of the different kinds of life on earth.
The total carbon in all living things amounts to 550 billion metric tons, they wrote. A metric ton is 2,200 pounds.
The weight of all the world’s plants is an estimated 450 billion metric tons.
The world’s bacteria weigh 70 billion metric tons.
All the world’s animals weigh only 2 billion metric tons, of which 1 billion tons consists of arthropods (including insects).
All the world’s humans total a mere 60 million metric tons.
Put another way, life on earth is, by weight, 82 percent plants, 13 percent bacteria and 5 percent everything else, of which 0.01 percent is human life.
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