Chickens are now the most numerous vertebrate on the planet. 66 billion of them are slaughtered for food annually. And these are not your father’s chickens either, because these birds sprout legs and thighs that have been genetically modified and are significantly larger than their predecessor’s. These bird’s existence is yet another example of humanity’s impact here, on God’s little golf ball.
We are now living in the Anthropocene epoch. This is an era that is marked by significant human impact on Earth’s geology and ecosystems, including, but not limited to, climate change. This was the thesis of Dr. TR Kidder’s talk, The Anthropocene Era: Have Humans Become a Greater Force Than All of Nature? He is the chairman of Washington University’s Anthropology Department and was this month’s speaker, at last night’s Science on Tap.
Kidder raised the question, in future epochs, will any signs of man’s existence remain? There is no need to worry about that. The birth of humanity has always been coincidental with the creation of garbage. Anthropologists rely upon first finding human garbage, as a means to search for human bones.
Examples of mankind’s impact on this blue marble abound. Plastiglomerate, stone that contains mixtures of sedimentary grains, and other natural debris and is held together by hardened molten plastic can be found everywhere. 500 million tons of elemental aluminum has been smelted, not a naturally occurring material. 50 billion tons of concrete has been mixed. That is enough concrete to cover the surface of the Earth to a meter’s depth. The geologic record of our existence will not soon disappear.
Archeologists like to separate earth’s history into neat little time periods. The K-T boundary, the geologic transition between the Cretaceous and Tertiary eras is a excellent facilitator for this behavior. Similarly, Kidder proposes July 16, 1945 as the beginning of the Anthropocene epoch. Not that that is when this era began. In actually began much earlier, but on that day near Alamogordo, NM, the first atom bomb was detonated. In subsequent years, through the sixties, following nuclear tests have blanketed the planet with a layer of Strontium-90, a golden spike that will crisply delineate in a geologic timeframe what preceded man and what came afterwards. Because chemically strontium mimics calcium, any child of the sixties has Strontium-90 embedded in their teeth and bones. Coincidentally, Strontium-90 is already being used to detect fine wine fraud.
The current CO2 concentration in the atmosphere is now above 400 ppm, a level that has not been seen on this planet for 3 million years. No person alive today will see atmospheric CO2 concentration fall below that level. You could say that global warming is now sorta baked into the equation. It is generally thought that the rise of CO2 levels and the advent of global warming began in the Industrial Revolution, but polar ice core records show that CO2 rise began with the start of the Holocene epoch, some 11,700 years ago and coincided with the first farms. Slash and burn agriculture released CO2, but more importantly, the people of the cleared fields began changing the face of the earth. The last most significant decrease in CO2 levels occurred around 1610 or more than a hundred years after Columbus sailed. In between that date and his first voyage, it is estimated that some 20 million Native Americans died. Their deaths and the brief decline of agriculture in the New World is believed to be the cause for that CO2 dip.
Are we hard-wired for destruction? Our record as a species indicates that we are, even as far back as paleolithic man, on whom the extinction of many species of mega-fauna can be pinned. At this crossroads, we need to become better, more thoughtful stewards, but that is against our nature. Humanity has always had to wrestle with problems that offer either a pay now or pay later proposition. People invariably choose later, even though later is much more expensive.
Kidder’s talk was very informative, if a bit depressing. At least it took our minds off of the Corona virus for a while. I love the new venue for these talks, the Jefferson Ballroom on Chouteau. Anne and I shared a PW Pizza for dinner. We’ve been promised a much lighter topic for next month’s talk, Helium.