written 7 Nov 2021
published 14 Nov 2021
The theory of an asteroid impact ending the dinosaurs had been around for some time, but the first impact evidence was published in the late 70's, with the report of a thin layer of soil enriched with iridium, an element rare on Earth but common in asteroids. This layer, found around the world, also contained grains of quartz that had been deformed by a high pressure shockwave, and had soot from massive forest fires. In 1990, the crater was located, despite being buried under deep sediments, using gravity field measurements and seismic profiling.
Humanity has produced several global impacts of our own, although over longer time periods and with a lot less energy involved.
From 1951 until 1962, humans detonated 528 nuclear devices in the atmosphere, releasing over 400 megatons of energy, the equivalent of 29,000 Hiroshima sized blasts. The winds distributed this radioactive material around the world. Kodak noticed that the film it produced was fogged at certain times, and discovered it was associated with tests in Nevada. The company had enough economic clout to demand the government let them know when a test was scheduled, so they could halt production, even though none of the people living downwind were notified.
To this day, all the steel smelted since atmospheric testing began has traces of radionuclides. Very sensitive radiological instruments have to be made from steel smelted before 1940. One of the largest sources are the 52 German war ships sunk at the British Navy base of Scapa Flow in 1919, after the first World War.
Another global human impact is the wide spread pollution by plastic. Since 1950, over 9 billion tons of plastic have been manufactured, 380 million tons in the last year alone. Plastic trash has been found everywhere, from the peak of Mount Everest to the depths of the Mariana Trench. While undigestible, the molecular structure of plastic breaks down into small pieces, creating microplastic, which is now in the air, rain and snow. Plastic bio accumulates and is in everything we eat.
Microplastics entering the human body through ingestion or inhalation can lead to an array of health impacts, including inflammation, cancer, and cardiovascular diseases, and exposes us to chemicals found in plastics that are known to be harmful. These chemicals, called endocrine disruptors, mimic hormones and have been linked to a variety of health problems, including obesity, organ problems, developmental delays in children, and reproductive issues.
Chemical contamination is also widespread, particularly the family called PFASs (perfluoroalkyl substances), known as "forever chemicals". First introduced in 1946 by Dupont as Teflon for non-stick cookware, they are now in a staggering array of consumer and commercial products. PFASs are used in fire retardants, and oil and water stain repellents in clothing, carpets, and furniture. They are used extensively to coat paper and cardboard wrappers for fast food take-out food containers and bakery goods. One of the most widely used class of chemicals, PFASs now contaminate water, and soil, where they never break down and bio accumulate in our bodies.
As early as 1956, research began showing health problems. Very small quantities are linked to cancer, reproductive and immune systems harm, as well as other diseases. Researchers looking to document this contamination found everyone has detectable levels in their blood, including new born babies. The only samples found to be free from PFASs were blood the Army had taken before the Korean war, and stored for research.
The world is connected, and we ignore that fact at our peril. Business never considers the larger impact of their actions, if they can hide the consequences. That is the nature of "externalized costs". They make the profit and someone else pays the cost. Our technology is so potent that we now see global consequences, including declining birth rates, wide spread chronic diseases, degraded biological systems, and of course, accelerating climate change. To survive, an evolution of consciousness is required, including whole systems thinking at every level.
