May 24, 2018

Groundbreaking assessment of all life on Earth reveals humanity’s surprisingly tiny part in it as well as our disproportionate impact

This is a very silly article, replete with implicit but unargued assumptions -- such as the implicit claim that "we" are in some way responsible to make good -- or at least apologize for -- all the damage that all humans throughout history have ever done.

From Trilobites to the dinosaurs, extinctions are what nature does.  Of all species that have existed on Earth, 99.9 percent are now extinct. And, of all the extinctions that ever happened, most by far happened long before human beings were on the scene. Humans were NOT reponsible for the extinction of the dinosaurs, for instance.

And even in the human era, modern sensitivities were virtually unknown.  The megafauna of Australia were extinguished by Australian Aborigines, for instance.  I feel no guilt over that. Primitive people are often hard on the environment (pace the fictional Chief Seattle) but how am I responsible for that? It's a basic principle of natural justice that I am not to blame for the deeds of others.

Nonetheless, I am enough of a modern man to feel some regret about some recent extinctions(passenger pigeons anyone?).  But should I?  That leads us into very rarefied areas of moral philosophy that are not all congenial.  Peter Singer, for instance, is an eminence in that field and his cogitations lead him to some very objectionable conclusions, like the permissibility of infanticide.

So feeling that recent extinctions are bad is just that: feelings. A more intellectual justification for concern awaits. Excerpts only below:


Humankind is revealed as simultaneously insignificant and utterly dominant in the grand scheme of life on Earth by a groundbreaking new assessment of all life on the planet.

The world’s 7.6 billion people represent just 0.01% of all living things, according to the study. Yet since the dawn of civilisation, humanity has caused the loss of 83% of all wild mammals and half of plants, while livestock kept by humans abounds.

The transformation of the planet by human activity has led scientists to the brink of declaring a new geological era – the Anthropocene. One suggested marker for this change are the bones of the domestic chicken, now ubiquitous across the globe.

The new work reveals that farmed poultry today makes up 70% of all birds on the planet, with just 30% being wild. The picture is even more stark for mammals – 60% of all mammals on Earth are livestock, mostly cattle and pigs, 36% are human and just 4% are wild animals.

The destruction of wild habitat for farming, logging and development has resulted in the start of what many scientists consider the sixth mass extinction of life to occur in the Earth’s four billion year history. About half the Earth’s animals are thought to have been lost in the last 50 years.

But comparison of the new estimates with those for the time before humans became farmers and the industrial revolution began reveal the full extent of the huge decline. Just one-sixth of wild mammals, from mice to elephants, remain, surprising even the scientists. In the oceans, three centuries of whaling has left just a fifth of marine mammals in the oceans.

The researchers calculated the biomass estimates using data from hundreds of studies, which often used modern techniques, such as satellite remote sensing that can scan great areas, and gene sequencing that can unravel the myriad organisms in the microscopic world.

The researchers acknowledge that substantial uncertainties remain in particular estimates, especially for bacteria deep underground, but say the work presents a useful overview.

SOURCE 




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