Gdoc/Admin

Humans make up just 0.01% of Earth's life — what's the rest?

How is life on Earth distributed across the taxonomic kingdoms? Humans make up just 0.01% of life: but we've had much larger impacts on shaping the animal kingdom. Livestock now outweighs wild mammals and birds ten-fold.

Our planet is home to an incredible diversity of organisms. What does Earth's biodiversity look like in the big picture?

In this post, I provide an overview – with a summary graphic – of Earth's biomass, how it is distributed between taxa (the taxonomic group of organisms), and the environments within which they live. This summary is based on the findings of research by Bar-On, Phillips & Milo published in the Proceedings of the National Academy of Sciences (PNAS).1

Humans account for just 0.01% of biomass

There are several ways we can answer the question of how much life is on Earth. We could, for example, count the number of species, population sizes, or the number of individual organisms. But these metrics can make it difficult to compare between taxa: small organisms may have a large population but still account for a tiny percentage of Earth's organic matter.

For a meaningful comparison, Bar-On et al. (2018) quantified life using the metric of biomass. Biomass is measured here in tonnes of carbon as it is a key building block of life.2

In the graphic below, I summarize global biomass distribution by taxonomic kingdom (on the left), with a magnified snapshot of the animal kingdom (on the right).

What are the stand-out points?

Livestock outweighs wild mammals and birds ten-fold

Humans comprise a tiny share of life on Earth — 0.01% of the total and 2.5% of animal biomass (animal biomass is shown in the right-hand box on the visualization above).

But we are also responsible for the animals we raise. Humans alone may seem insignificant, but our hunger for raising livestock means we have played a major role in shifting the balance of animal life: livestock account for 4% of animal biomass.4

Livestock accounts for more biomass than all humans on Earth, more than 50% greater than humans.

And livestock accounts for much more than all wildlife: Wild mammals and birds collectively account for only 0.38% — livestock, therefore, outweighs wild mammals and birds by a factor of ten.5

Endnotes

  1. Bar-On, Y. M., Phillips, R., & Milo, R. (2018). The biomass distribution on Earth. Proceedings of the National Academy of Sciences, 201711842. Available at: http://www.pnas.org/content/115/25/6506.

  2. To calculate the biomass of a taxonomic group, the researchers multiplied the carbon stock for a single organism by the number of individuals in that group. In humans, for example, they calculate the average carbon quantity of a person and multiply it by the human population. If you're interested in comparing biomass and the abundance of different taxonomic groups, you can explore this here.

  3. We can calculate our share of total biomass as 0.06 billion tonnes C (human biomass) / 546 billion tonnes (total biomass) * 100 = 0.01%.

  4. Figures for livestock don't include fish catch or farming — of course, these also had significant impacts on marine life.

  5. Poultry livestock accounts for 0.2 percent of animal biomass — more than twice that of wild birds. Bar-On et al. (2018) estimate global poultry biomass to be 0.005 billion tonnes of carbon. This is approximately 0.2 percent of animal biomass (= 0.005 / 2.4 * 100). Wild birds account for only 0.08 percent of animal biomass.

Cite this work

Our articles and data visualizations rely on work from many different people and organizations. When citing this article, please also cite the underlying data sources. This article can be cited as:

Hannah Ritchie (2019) - “Humans make up just 0.01% of Earth's life — what's the rest?” Published online at OurWorldInData.org. Retrieved from: 'https://ourworldindata.org/life-on-earth' [Online Resource]

BibTeX citation

@article{owid-life-on-earth,
    author = {Hannah Ritchie},
    title = {Humans make up just 0.01% of Earth's life — what's the rest?},
    journal = {Our World in Data},
    year = {2019},
    note = {https://ourworldindata.org/life-on-earth}
}
Our World in Data logo

Reuse this work freely

All visualizations, data, and code produced by Our World in Data are completely open access under the Creative Commons BY license. You have the permission to use, distribute, and reproduce these in any medium, provided the source and authors are credited.

The data produced by third parties and made available by Our World in Data is subject to the license terms from the original third-party authors. We will always indicate the original source of the data in our documentation, so you should always check the license of any such third-party data before use and redistribution.

All of our charts can be embedded in any site.