Can We Be Sure We're the First Industrial Civilization on Earth?
In a new paper, Gavin Schmidt of the NASA Goddard Institute for Space Studies and Adam Frank from the University of Rochester ask a provocative question [open, DOI: 10.1017/S1473550418000095] [DX]: Could there have been an industrial civilization on Earth millions of years ago? And if so, what evidence of it would we be able to find today?
The authors first considered what signs of industrial civilization would be expected to survive in the geological record. In our own time, these include plastics, synthetic pollutants, increased metal concentrations, and evidence of large-scale energy use, such as carbon-based fossil fuels. Taken together, they mark what some scientists call the Anthropocene era, in which humans are having a significant and measurable impact on our planet.
The authors conclude, however, that it would be very difficult after tens of millions of years to distinguish these industrial byproducts from the natural background. Even plastic, which was previously thought to be quite resistant, can be degraded by enzymes relatively quickly. Only radiation from nuclear power plants—or from a nuclear war—would be discernible in the geological rock record after such a long time.
Anonymous Coward says "I told you so!" and starts babbling about megaliths.
Related: Homo Sapiens Began Advanced Toolmaking, Pigment Use, and Trade Earlier Than Previously Thought
(Score: 2) by JoeMerchant on Friday April 20 2018, @03:52AM
Certain forms of buried stuff also cease to degrade when buried below the water table.
During an exceptional drought, we dug a pit about 30' deep near a river, the bottom 4' of that pit were still under water, and in that water we pulled up an amazingly preserved tree trunk. It didn't last long after it hit the air, but that tree trunk had been buried in the sand for a long, long time - at least many thousands of years. It was covered by two undisturbed layers of phosphate (AFAIK from when the area, now 30' above sea level, was under the ocean), and also a top layer of "hardpan" (iron oxide from the seasonal top of the water table) several inches thick.
The same happens with old shipwrecks, the water preserves them, like this one: http://www.jacksonville.com/news/20180328/old-shipwreck-washes-ashore-in-ponte-vedra-beach [jacksonville.com]
🌻🌻 [google.com]