[D66] Are we headed towards the sixth mass extinction?

[René Oudeweg]

thedailystar.net 
<https://www.thedailystar.net/opinion/views/news/are-we-headed-towards-the-sixth-mass-extinction-3297366> 



  Are we headed towards the sixth mass extinction?

Quamrul Haider Sun Apr 16, 2023 03:00 PM Last update on: Sun Apr 16, 
2023 05:57 PM
7–8 minutes
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Surreal as it may seem, we have clearly embarked on the path to 
self-annihilation.

Over the past 540 million years, a short period of time on the 
geological scale, there were five events of mass extinction, caused by 
such things as severe ice age, an asteroid impact, invasive species 
taking over the planet, reconstruction of the Earth's crust some 250 
million years ago, and other forces of nature. The most recent was 66 
million years ago, which led to the extinction of dinosaurs. During each 
extinction, more than 75 percent of all species on the planet died.

Extinction is also a natural process. A species may become extinct and 
be replaced by another species, or it may gradually evolve into one or 
more new species. An important aspect of natural extinction is that 
niches remain occupied, but the species filling them change radically. 
The demise of the dinosaurs, though not natural, gave new species an 
opportunity to grow, from which human beings eventually evolved.

With the introduction of humans as an ecological factor, there has been 
a shift from the gradual, natural replacement-type extinction to an 
abrupt niche-emptying extinction. The way humans have attacked the 
species of the world varied from outright assault to insidious nibbling, 
both of which have the same destructive result. Many animals disappeared 
simply because they were edible. Others became extinct because they were 
fashionable in human eyes. The rate of extinction is now about 1,000 
times faster than before humans arrived.

It leads one to wonder whether we are on track for the sixth mass 
extinction. Many scientists believe that the question is not "whether," 
nor "if," but "when." And this time, the cause will not be global 
cooling or asteroid impact. It will be the work of a single species ‒ 
/Homo sapiens/ – driving themselves to extinction.

The UK-based Global Challenges Foundation lists nuclear war, pollution 
and climate change, overpopulation, biotechnology, and pandemics as the 
most viable threats to the existence of humans.

Of the many possible scenarios, nuclear conflict is the most likely one 
by which human civilisation will become extinct. Our vulnerability to 
this threat is growing because of the escalating political tensions 
between nuclear-armed superpowers.

In an open threat of a nuclear war, Russia's Security Council Deputy 
Chairman Dmitry Medvedev did not mince words when he publicly said that 
a defeat for Russia in the war against Ukraine could provoke a nuclear 
war. Meanwhile, the head of the Russian Orthodox Church, Patriarch 
Kirill, warned that "an attempt to destroy Russia [by Nato using Ukraine 
as a proxy] will mean the end of the world."

    With the entrance of man as an ecological factor, there has been a
    shift from the gradual, natural replacement-type extinction to
    abrupt niche-emptying extinction.

Yes, the patriarch is spot on. Today, the US, Russia, and China possess 
enough nuclear weapons to kill every man, woman, and child on this 
planet. If any of these countries initiates the use of such weapons, 
especially against another one that possesses them in abundance, the 
inevitable result will be the annihilation of the human race.

If we are spared the nuclear holocaust, then pollution and anthropogenic 
climate change will be responsible for our extinction. Today, we live on 
a planet poisoned by toxins dumped by us. The toxins are in the food we 
eat, the water we drink, and the air we breathe. As the renowned 
explorer and environmentalist Jacques Cousteau said, "Water and air, the 
two essential fluids on which all life depends, have become global 
garbage cans."

Such a society cannot live forever.

Climate change per se is unlikely to cause our extinction. However, the 
synergistic feedback of the continued emission of planet-warming 
greenhouse gases (GHGs) can trigger the onset of "runaway greenhouse 
effect," which will eventually turn the Earth into an inferno with 
virtually no life. Several billion years ago, Venus was an Earth-like 
planet with an abundance of water in oceans overlain by an oxygen-rich 
atmosphere. The current hellish condition on Venus where the surface 
temperature is a blistering 460 degrees Celsius was caused by runaway 
greenhouse effect.

A rapidly growing human population is putting us in the throes of 
extinction. With a population that increased three-fold since 1950, 
food, water, and a whole lot more required for sustenance of life in the 
future will be in short supply. In fact, we are surviving today by 
stealing /from/ the future. Hence, it is not unlikely that once the 
population reaches a "critical mass," natural resources vital to our 
survival will not be adequate enough to support us, unless we can 
replace them with sustainable alternatives. As a result, starvation will 
bring us face-to-face with extinction.

The misuse of biotechnology is another existential risk. With the 
advancement in DNA manipulation technology, it is quite likely that 
scientists working for a roguish state actor or a terrorist group can 
engineer a "superbug" for biological warfare, and in the process 
obliterate our entire civilisation. Besides, the abuse of biotechnology 
to develop deadly, quick-spreading pathogens that can hasten our 
extinction cannot be ruled out. For example, the pathogen often called 
the Spanish Flu, which killed an estimated 50 million people worldwide 
in 1918 and 1919, was resurrected by a group of US scientists in 2005. 
And a professor in the Netherlands came under fire in 2011 when he 
engineered a deadly, airborne version of the flu virus and attempted to 
publish the details of his work.

We cannot rule out the possibility of fast-spreading devastating 
diseases, such as Covid-19, which, according to the World Health 
Organization (WHO), claimed at least three million lives since 2020. In 
the past two millennia, besides the Spanish Flu, the other pandemics 
that can be labelled as global catastrophes of a bigger magnitude were 
the Black Death of the 1340s that felled more than 10 percent of the 
world population, and the great Plague of Justinian in 541 and 542 that 
wiped out an estimated 13-17 percent of the global population at that time.

Surreal as it may seem, we have clearly embarked on the path to 
self-annihilation. Indeed, several recently published scientific studies 
warn that the sixth mass extinction is already underway. Lest we forget, 
our ancestors – Neanderthals, Denisovans, /Homo erectus/ – became 
extinct, leaving just their descendants, the /Homo sapiens/, to follow 
them. The question is: How soon?

/*Dr Quamrul Haider* is a professor of physics at Fordham University in 
New York, US./
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