31 May 2017
A new paper is out in the AGU journal GeoHealth and it shows something that is truly remarkable.
Researchers looked at lead concentrations in an ice core from a glacier on the Swiss-Italy border. They wanted to know if there was a natural background of lead pollution and they pretty much got there answer.
There is not.
What’s remarkable though is how they found out: The Black Death.
When the mass dying began in 1348, iron smelting stopped. No one needed new iron, because there was plenty of iron around since many of those who owned it were now dead. The atmospheric lead levels dropped to almost undetectable levels during the great dying, and the graph below shows it:
When I was at the NEEM ice core site in Greenland, I saw the volcanic dust signature in the ice core from an Icelandic volcano that erupted in the 1780’s, and Dr. Ben Franklin wrote of this volcano, while coming back to America from Paris in the 1780’s. Ice cores truly are atmospheric time machines. They’ve shown us how are climate has changed, and now they show us that lead in the atmosphere is man-made, and its been there for at least 2000 years.