Sure, the human race doesn’t make up much of all the living beings on this planet but that doesn’t keep us from tearing the planet apart. We have caused some serious damage to the number of wild animals across the globe and now that the statistics are in, this reality is even more devastating.
A study that was recently published in the journal Proceedings of the National Academy of Sciences found that humans have caused the loss of 83 percent of all wild animals. No, this is not a joke. This study is the first to estimate the weight of every living creature and also noted that bacteria account for about thirteen percent and the mass of life in the oceans is only about one percent of all biomass. Isn’t that insane?
This study was titled ‘The Biomass distribution on Earth‘ and it is significant because it provides a holistic view of the composition of the biosphere and allows us to observe broad patterns over taxonomic categories, trophic modes, and geographic locations. Understanding the structure of the biosphere as well as its dynamics is important.
According to this study, the impact of humanity on the biosphere is as follows:
Over the relatively short span of human history, major innovations, such as the domestication of livestock, adoption of an agricultural lifestyle, and the Industrial Revolution, have increased the human population dramatically and have had radical ecological effects. Today, the biomass of humans (≈0.06 Gt C; SI Appendix, Table S9) and the biomass of livestock (≈0.1 Gt C, dominated by cattle and pigs; SI Appendix, Table S10) far surpass that of wild mammals, which has a mass of ≈0.007 Gt C (SI Appendix, Table S11). This is also true for wild and domesticated birds, for which the biomass of domesticated poultry (≈0.005 Gt C, dominated by chickens) is about threefold higher than that of wild birds (≈0.002 Gt C; SI Appendix, Table S12). In fact, humans and livestock outweigh all vertebrates combined, with the exception of fish. Even though humans and livestock dominate mammalian biomass, they are a small fraction of the ≈2 Gt C of animal biomass, which primarily comprises arthropods (≈1 Gt C; SI Appendix, Tables S13 and S14), followed by fish (≈0.7 Gt C; SI Appendix, Table S15). Comparison of current global biomass with prehuman values (which are very difficult to estimate accurately) demonstrates the impact of humans on the biosphere. 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 (SI Appendix, Pre-human Biomass and Chordates and Table S11). Intense whaling and exploitation of other marine mammals have resulted in an approximately fivefold decrease in marine mammal global biomass [from ≈0.02 Gt C to ≈0.004 Gt C (31)]. While the total biomass of wild mammals (both marine and terrestrial) decreased by a factor of ≈6, the total mass of mammals increased approximately fourfold from ≈0.04 Gt C to ≈0.17 Gt C due to the vast increase of the biomass of humanity and its associated livestock. Human activity has also impacted global vertebrate stocks, with a decrease of ≈0.1 Gt C in total fish biomass, an amount similar to the remaining total biomass in fisheries and to the gain in the total mammalian biomass due to livestock husbandry (SI Appendix, Pre-human Biomass). The impact of human civilization on global biomass has not been limited to mammals but has also profoundly reshaped the total quantity of carbon sequestered by plants. A worldwide census of the total number of trees (32), as well as a comparison of actual and potential plant biomass (17), has suggested that the total plant biomass (and, by proxy, the total biomass on Earth) has declined approximately twofold relative to its value before the start of human civilization. The total biomass of crops cultivated by humans is estimated at ≈10 Gt C, which accounts for only ≈2% of the extent total plant biomass (17).
Clearly, humanity plays a very dominant role on Earth itself. Another important thing to note is that the study also revealed that farmed poultry makes up about 70 percent of all birds. That means only thirty percent of all birds are ‘wild.’ This is sickening, is it not?
There is a lot more to our impact than we realize and we need to bring awareness to it. Humans are great at exploiting natural resources and it’s kind of devastating. What do you think about all of this?
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