The biomass of humans


in Geek stuff, Science, The environment

Sightline Daily has some interesting numbers up on the relative biomass of human beings, domesticated animals, and wild animals. Apparently, just humans have eight times as much mass as all the wild vertebrates on land. Our mass approximately equals that of all the fish and whales in the ocean. Things are even more dramatic when you factor in domesticated animals. They contain 100 megatonnes of carbon – 20 times as much as there is in all the wild vertebrates on land.

The figures certainly make you think about ecological footprints in a more direct way. They also say something about energy. It seems fair to say that one major factor affecting the total biomass of wild animals is the amount of energy they are able to access. To what extent does our inflated biomass result from unsustainable energy use? Will we be able to maintain it when we can no longer count on ever-increasing production of fossil fuels?

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{ 6 comments… read them below or add one }

Tristan October 17, 2008 at 8:49 am

Is this a disguised and PC way of talking about over-population?

Milan October 17, 2008 at 10:01 am

Clearly, it relates to population.

Even so, I thought it was a different enough presentation to be worth noting. Somehow “as massive as all the fish and whales in the sea” seems more tangible than “6.7 billion.” It also gives one a sense of why we are proving so effective at stripping the seas of life.

Bloix October 21, 2008 at 11:08 am

“To what extent does our inflated biomass result from unsustainable energy use?”

Our inflated biomass results almost entirely from the synthesization of ammonia, which is the basis for artificial fertilizer. The patent for the process was filed 100 years ago this month, in the most important scientific advance of the 20th century, by the German chemist Fritz Haber. The population increase from 1.6 billion in 1900 to 6.5 billion today is due in the main to the Haber-Bosch process, which broke the Malthusian bounds on food production.

Synthetic ammonia is made by combining hydrogen derived from petroleum or natural gas with nitrogen in the atmosphere, and requires large amounts of energy, also usually produced using petroleum or natural gas, so the answer to your question is, “to a very large extent.”

see, e.g.,

Milan October 21, 2008 at 11:21 am

Ammonia synthesis is described at some length in: Something New Under the Sun: An Environmental History of the 20th Century

Given how most fertilizers are produced from fossil fuels, they represent yet another way in which hydrocarbon dependence makes our society unsustainable.

Milan January 12, 2010 at 6:26 pm

Those human biomass figures could go up a lot; by 2100, the United States may have one billion inhabitants.

. June 7, 2011 at 6:08 pm

Almost 90% of the world’s plant activity, by some estimates, is to be found in ecosystems where humans play a significant role. Although farms have changed the world for millennia, the Anthropocene advent of fossil fuels, scientific breeding and, most of all, artificial nitrogen fertiliser has vastly increased agriculture’s power. The relevance of wilderness to our world has shrunk in the face of this onslaught. The sheer amount of biomass now walking around the planet in the form of humans and livestock handily outweighs that of all other large animals. The world’s ecosystems are dominated by an increasingly homogenous and limited suite of cosmopolitan crops, livestock and creatures that get on well in environments dominated by humans. Creatures less useful or adaptable get short shrift: the extinction rate is running far higher than during normal geological periods.

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