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Surveying archaeologists across the globe reveals deeper and more widespread roots of the human age, the Anthropocene
Surveying archaeologists across the globe reveals deeper and more widespread roots of the human age, the Anthropocene
Examples of how human societies are changing the planet abound – from building roads and houses, clearing forests for agriculture and digging train tunnels, to shrinking the ozone layer, driving species extinct, changing the climate and acidifying the oceans. Human impacts are everywhere. Our societies have changed Earth so much that it’s impossible to reverse many of these effects.
Some researchers believe these changes are so big that they mark the beginning of a new “human age” of Earth history, the Anthropocene epoch. A committee of geologists has now proposed to mark the start of the Anthropocene in the mid-20th century, based on a striking indicator: the widely scattered radioactive dust from nuclear bomb tests in the early 1950s.
But this is not the final word.
Not everyone is sure that today’s industrialized, globalized societies will be around long enough to define a new geological epoch. Perhaps we are just a flash in the pan – an event – rather than a long, enduring epoch.
Others debate the utility of picking a single thin line in Earth’s geological record to mark the start of human impacts in the geological record. Maybe the Anthropocene began at different times in different parts of the world. For example, the first instances of agriculture emerged at different places at different times, and resulted in huge impacts on the environment, through land clearing, habitat losses, extinctions, erosion and carbon emissions, forever changing the global climate.
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Re-Inhabiting Planet Earth
Re-Inhabiting Planet Earth
“I believe that for a moment I thought the explosion might set fire to the atmosphere and thus finish the Earth, even though I knew that this was not possible.”
These words of Manhattan Project physicist Emilio Segre, quoted by Richard Rhodes in his book The Making of the Atomic Bomb, refer to the Trinity blast on July 16, 1945, at Alamogordo, N.M., the first atomic explosion in history and, so it appears, a turning point for all life on this planet.
The atmosphere didn’t catch fire at 5:30 that morning, but Segre’s words remain relevant, sort of like radioactive fallout. They encapsulate what may be history’s ultimate moment of human arrogance: the belief in a sense of separateness from and superiority to nature so thorough that we have, with our monstrous intelligence, the ability and therefore the right to play Bad God and make the whole planet go poof.
Turns out the Trinity test set into motion something even more profound than the nuclear era. The bomb didn’t just “defeat” Japan and define the Cold War, with its suicidal nuclear arms race. It is also, at least symbolically, marks the beginning of what has come to be known as the Anthropocene: an era of profound climate and “Earth system” destabilization caused by human activity and therefore, like it or not, establishing humans as co-equal participants in activity of the natural world.
There’s more to this “co-equal” status than nuclear weapons, of course. They may be the tip of our arrogance, but we’ve been exploiting and rearranging the planet for nearly 12,000 years, since the beginning of the era we are now leaving, the Holocene, an era of climate stability in which human civilization and all written history emerged.
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Trinity: 70 Years Later
Trinity: 70 Years Later
It was 70 years ago, on July 16, 1945, that the first atomic bomb, named Trinity, was exploded at the White Sands Proving Ground, the nuclear test site near Alamagordo, NM. It was an event that changed world history forever, and created new health and security threats that still plague all life on this planet.
Details of Trinity have been documented before, but merit a recap, since memories may fade with the passage of so many years. The collision of two forces – the discovery of atomic fission and the rise of Nazi Germany – resulted in the creation of the Manhattan Project in late 1942. Fearful that the Germans would develop and use
a nuclear weapon, President Franklin D. Roosevelt directed the U.S. army to develop such a weapon first. Working furiously, scientists had developed enough nuclear material for a bomb in less than three years. Some were worried that Germany would develop a bomb, but historians have discounted that, and the country was defeated, but American forces were still engaged against Japan.
Before a bomb could be used, a test was needed. A 100-foot tower for the bomb and two trenches for observers were constructed.
The trenches were 10 and 17 miles away, as nobody really knew how powerful the blast would be.
At 5:29 local time, a deafening roar went up, and a blinding flash illuminated the desert, visible 200 miles away. A gaping crater 10 feet deep and 1100 feet in diameter was formed. The shock wave from the explosion could be felt for more than 100 miles. The yield of the plutonium-based bomb was estimated at 23,000 tons of TNT. To maintain secrecy, the Army issued a press release, stating that an “ammunition magazine” had exploded, without anyone being injured.
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