The ice tells the story

Now here's an insight into human history:

A recent study published in Proceedings of the National Academy of Sciences tied the rise and fall of lead in Arctic ice samples to economically significant historical events over the course of the last 2,500 years, from the Roman Empire to the present. Climate scientists and historians worked together to conduct the research, using data from 13 ice samples taken from different regions around the Arctic.

Atmospheric lead pollution and economic growth shared a “direct link,” said study coauthor Nathan Chellman, because of lead’s ties to money. Production of precious ores used for currency, especially silver, was pretty much the only source of lead pollution for many centuries.

... For most of history, wars and plagues corresponded with economic decline. That translated into dips in lead levels in the ice that formed during those years. Periods of growth and prosperity, on the other hand, were marked by increasing levels of lead pollution. That shifted into overdrive in the mid-1700s, when the Industrial Revolution brought rapid technological developments.

Grist, July 15, 2019

Those technological developments increased lead pollution exponentially over previous levels.

Have these scientists discerned the cycle of human species development? First we become really smart and improve living standards and life expectancy, then we poison ourselves and everything else and die back, only to start the sequence again (at least so long as the damage was localized)?

Those ice cores show a lot about increasing climate chaos too.