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3.4: In What Ways Are Humans the Most Dangerous Species

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    76113
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    Reasons why humans have become so dangerous include human intelligence and adaptability, easy access to abundant fungible energy, an attitude of superiority over nature and hubris. These enabled humans to constantly develop increasingly complex technologies that empowered humans to do things much more easily and rapidly than they could do otherwise. More recently, access to abundant cheap energy enabled these technologies to progress and develop at a rate beyond our ability to recognize and acknowledge how human actions affect both humans and the non-human world. Our philosophy is more like ‘We can do it, so let’s do it.’ as opposed to ‘We can do it, but should we, and why’? As a result, humanity developed the perspective of being ‘above’ nature, more powerful than nature, a ‘belief’ that it was exempt from the limits of nature common to other life. This impression is epitomized in Genesis 1, p. 28 (NIV), “God blessed them and said to them, ‘Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish of the sea and the birds in the sky and over every living creature that moves on the ground.’ This perspective of moral exceptionalism and anthropocentrism was elaborated later by philosophers and scientists such as Francis Bacon, Rene Descartes and Isaac Newton (White, 1967).

    Frankly, in some aspects we are different from the rest of nature and we do have exceptional gifts which we have used to great effect, but often with little consideration as to the consequences of our actions. Dilworth (2010, p. 2), exploring our current ecological problems, wrote, “Our species is special in being the only species to have constantly developed technology ….and … it is just this technological innovativeness that is responsible for our present ecological predicament. In sum, we have simply been too smart for our own good. However, in this ‘success,’ humanity seems to have forgotten its roots, and in terms of human development and progress, humans seem to have forgotten that what was created in Step 1 — a healthy Earth capable of supporting life indefinitely — will always be a fundamental requirement for all human life and progress, and must retain primacy. Instead, humanity seems to want to demonstrate its ingenuity by maintaining its material progress with little regard to what it is doing to the Earth. How ‘smart’ is that?

    As individuals we likely consider the human species as the most intelligent species, but with respect to reproduction, our behaviour does not appear to be intelligent. For example, in 1800, the global human population was about one billion in 1800, 1.6 billion in 1900, 6.1 billion in 2000, 7.6 billion in 2018 and will be 10 billion in 2055. (For more information, see Worldometer.) Thus, while it took about 200 millennia to get to a population of one billion, it has taken only 220 years to multiply that eight times more. However, while the size of the Earth has not changed, many of its features and functions have been changed by humans so as to meet the needs of the growing population. Thus the forests, prairies and waters that covered much of Earth have been transformed for human needs, particularly in industry and food production (Hooke et al., 2012; Jackson, 2010). Humanity’s impact is profound.

    In 1997, Vitousek and coworkers estimated that “between one-third and one-half of the land surface of the Earth has been transformed by human action and that more atmospheric nitrogen is fixed by humanity than by all natural terrestrial resources combined, more than half of all accessible surface fresh water is put to use by humanity, and about one-quarter of the bird species on Earth have been driven to extinction” (Vitousek et al., 1997, p. 494). Other researchers agree (Erb et al., 2009; MEAB, 2005). Today, humans make up nearly 36% of the total biomass of all mammals. Domesticated mammals (cows, sheep, horses, etc) add another 60%; all the remaining mammals, the wild ones: the lions, elephants, bears, etc. form only 4% (Bar-On et al., 2018). Think about that! Of all the mammals, only four percent are not in the service of humans; all the rest are under human management, for our convenience, not necessarily our need.

    Humans may dominate mammalian biomass but they are only 0.03% of the total biomass of the Earth (Bar-On et al., 2018). As of 2012, about 41% of Earth’s ice-free lands were being used for human infrastructure needs: e.g. farms, ranching, logging, industry, cities, suburbs (Barnosky et al., 2014) and there is virtually no part of the Earth that is free of human effects. Talk about the tail wagging the dog.

    In 1972, Meadows and coworkers published The Limits to Growth, which explored the likely patterns of human population and resource consumption over the following 100 years or so. They concluded that if humanity did not soon constrain resource use, there would be a shortfall of resources sometime in this century. As well, the demands of a growing population would not be met, and pollution from resource extraction, industrial production, and material use would pose environmental problems. Although their predictions were harshly criticized, a 2004 update confirmed most of their conclusions while revising some of their timelines (Meadows et al., 2004). Since then, Turner (2008, 2014), Bardi (2011) and Jackson and Webster (2016) have also revisited the Meadows forecasts and found them generally, and unfortunately, ‘on target.’

    To quantitate the human impact on Earth, William Rees and Mathis Wackernagel (1996) developed the Ecological Footprint, an estimate of how much of Earth’s biological capacity is required by a given human activity or population. Today, it is estimated that every year the world’s population uses the equivalent of 1.7 Earths to provide the services we need, the resources we use, and to absorb our waste. (For more information, see the Global Footprint Network.) That is living like the ‘average’ global citizen. But if you are reading this book, you are probably not the average citizen. You likely live in Canada, the USA or Australia, where the footprint is not 1.7 Earths, but five Earths. Perhaps you live in Brazil where you need only two Earths, or the UK, France or Switzerland (three Earths). Imagine that all your income comes from interest generated by a trust fund. Sometimes, you need a bit more, and so you borrow from the principal. But if you don’t pay it back the trust fund eventually runs out; then most often, you will have to go to work, or maybe go on welfare, but somehow your needs will be met. Earth is humanity’s trust fund and we have borrowed from it for millennia with apparent impunity. Where do we go when Earth can’t provide? Mars?

    To characterize the manifestations of human impact, Johan Rockström and coworkers in 2009 identified nine ‘planetary boundaries’ or primary aspects of key Earth system processes that “define the safe operating space for humanity” (Rockström et al., 2009, p. 472). Three of these boundaries — climate change, global phosphorus and nitrogen cycles, and rate of biodiversity loss—have already been transgressed. Several others—ocean acidification (Feely et al., 2009), stratospheric ozone, freshwater use, and land use change—are close to breaching their limits. The two remaining — atmospheric aerosol loading and chemical pollution—have not yet been satisfactorily quantified because we lack reliable indices with which to measure their effects, but both are major causes of ill health and death in human and non-human life (Piqueras & Vizenor, 2016; Landrigan et al., 2017).

    It is obvious that we are using more than Earth can sustainably provide or renew, and Earth’s life support systems are starting to fail. This is termed overshoot and reflects the time when the population’s demand on an ecosystem exceeds the ability of the ecosystem to respond. Wherever we look, we see threats to human security arising from overshoot. Step 6 is already characterized by serious global ecosystem instability (Romm, 2010). Something has to give.

    The above paragraphs summarize a world whose life-supporting systems are deteriorating. Physical and biological limits ultimately govern human life and society and the current situation of breaching these limits and increasing the stresses on Earth’s physical and biological systems cannot last. Breaking the limits breaks the planet.

    Human existence depends on an acknowledgement of its dependence on nature. Humans, now more than ever in human history, must live their lives with the active and aggressive acceptance of this dependence in all their actions, plans, aspirations, teachings and beliefs.


    3.4: In What Ways Are Humans the Most Dangerous Species is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts.

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