Posts Tagged ‘Snowball Earth’

Cool: Species Nearly Destroyed All Life Before

August 8, 2018

Earth. The Dark Side. Homo. It has become standard to point out that the genus Homo may destroy life, or, our species, or, at least, civilization itself. This is related to the “Fermi Paradox” (“Where is everybody?” asked Enrico Fermi around 1950…) The idea was that civilizations self-destruct, hence no civilization is visible in the galaxy. To which I retorted that we overestimate the likelihood of advanced life in the galaxy, for a galactic sized number of reasons:

https://patriceayme.wordpress.com/2013/11/06/40-billion-earths-yes-no/

One argument I rolled out is that life was nearly extinguished on Earth by life itself: consider “Snowball Earth”. This weapon of mass life extinction was generated by the advancement of life itself. Let me quote myself:

“Primitive bacterial life is probably frequent. However advanced life (animals) is probably very rare, as many are the potential catastrophes. And one needs billions of years to go from primitive life to animals.

After life forms making oxygen on Earth appeared, the atmosphere went from reducing (full of strong greenhouse methane) to oxidizing (full of oxygen). As methane mostly disappeared, so did the greenhouse. Earth froze, all the way down to the equator:

When Snowball Earth Nearly Killed Life

Yet volcanoes kept on belching CO2 through the ice. That CO2 built up above the ice, caused a strong greenhouse, and the ice melted. Life had survived. Mighty volcanism has saved the Earth, just in time.

That “snowball Earth” catastrophe repeated a few times before the Earth oxygen based system became stable. Catastrophe had been engaged, several times, but the disappearance of oxygen creating life forms had been avoided, just barely.”

Intense chemical weathering by massive acid rain is the likely cause of the end of a period known as the Marinoan glaciation, which happened form 650 to 635 million years ago, according to a paper published in the journal PNAS. This was the last occurence when nearly all of the Earth’s land and seas were frozen over, known as snowball Earth, with glaciers as thick as 2km. Other times, on the right, Earth had no ice at the poles… Present day civilization can survive a warm Earth (right)… Not a Snowball. However, to get from what we have now to no ice, in a geological blink, means ultimate war…

What does this mean philosophically?

Most philosophical systems in the traditional sense don’t consider the truism that, to get creation, one needs destruction, and the more creation, the more destruction. Why? That sounds childish, thus unwise. But children encounter the primeval. Philosophy extended to religion revels in destruction. Actually the Deus/God/Allah destroys the entire universe to establish Heavens.

The universe is a brutal place: not only do planets get flung into space, stars explode, but even entire galaxies get destroyed. The universe is also a happening.

In the greater scheme of things, a war where, say, seven billion people got killed would be nothing special: that was the world population in 1803, when the imbecile Napoleon, having mightily endeavored to reestablish slavery, losing an army in the process, sold a third of the present day US to the USA for 11 million dollars.

In the movie Terminator, Artificial Intelligence takes over, causes a nuclear holocaust, and tries to extinguish humanity. It is more likely though that more and more formidable wars would accompany a Hot Earth scenario… which is what we are going towards, quickly. As I have argued in the past, 2C Is Too Much! Under 2C of global warming, a chain reaction of tipping point would unleash itself, and self-accelerate:

https://patriceayme.wordpress.com/2009/11/18/2-c-is-too-much/

Now the idea is hitting the mainstream, nine years later. See: “Trajectories of the Earth System in the Anthropocene” in the Proceedings of the National Academy of Sciences. There, scientists argue that there is a threshold temperature above which natural feedback systems that currently keep the Earth at a nice temperature (around 15 C, global) will unravel. At that point, a chain reaction of climate events will thrust the planet into a “hothouse” state. Though the scientists don’t know exactly what this threshold is, they said it could be as little as 2 degrees C (4 degrees F) of warming above preindustrial levels. We are above that half-way point…

As they put it in scientese: We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene. We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies. Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System—biosphere, climate, and societies—and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values.”

People are deeply unaware, they believe that the planet’s climate is more stable than it really is. The episodes of Snowball Earth show that this is not the case. This erroneous feeling of ecological stability is the main source of the indifference which brings the destruction of the planetary climate.

The apocalypse, in the greater scheme of things, is not apocalyptic. After all, an apocalypse, etymologically speaking, is just an uncovering… And this is precisely this normalcy of the abnormal, which will make go so smooth…

Patrice Ayme