The Spanish conquest of the Americas brought about the demise of such civilizations such as the mighty Incas and Aztecs, ravaged indigenous populations through disease, warfare and slavery, all but erased many important historic and cultural artifacts… and changed the climate of the Americas?
That’s what researchers at Ohio State University are suggesting in a study on the Quelccaya ice cap in Peru published in Proceedings of the National Academy of Sciences on Monday. The study says long before smog had settled over Los Angeles and Mexico City and factories from Shanghai to Chicago pumped toxins into the atmosphere, the Spanish were helping contribute to climate change thanks to their lust for precious metals.
Paolo Gabrielli of Ohio State University and other scientists measured a variety of trace elements—including lead, bismuth and arsenic—in the core of the Quelccaya glacier to study the history of mining and metallurgy in the region between 793 and 1989. They can do this because trace elements are spewed into the atmosphere during the extraction and refining of various metals and are deposited on the glacier.
What the scientists found was that while evidence showed a spike in trace element levels around 1480 – when the Incas began to expand their empire and use bismuth deposits to make a new type of bronze alloy – the period following the Spanish conquest of the Inca empire in 1533 saw a huge jump in the levels of chromium, molybdenum, antimony and lead that was not surpassed until the industrial revolution.
"The metallurgic activities of the Inca had most likely only a local impact on the environment surrounding their mining operations," said Paolo Gabrielli, a study author and research scientist at the Byrd Polar and Climate Research Center at Ohio State, in an email to the New Republic. "In contrast, the mining and metallurgic activities performed by the Spanish had an impact on the atmosphere of the entire South America continent."
The levels began to rise until 1700 and stayed steady until around 1830, which coincided with wars of independence throughout Spanish America when many of the machines and mines were destroyed by Republican fighters.
During that time, "rebel and royalist armies destroyed machinery, killed draft animals, and damaged mines and refineries," the researchers noted, according to the Smithsonian Magazine. "In addition, the scarcity of both [mercury] and labor for amalgamation, lack of transportation infrastructure, dearth of capital, and debilitating fiscal policies all contributed to stagnation in the mining industry during this time."
The new research also suggests that the start of the Anthropocene - the proposed epoch that began when human activities had a significant global impact on the Earth's ecosystems – might have begun earlier than the Industrial Revolution. Some researchers have put the start of the period as far back as the Greek, Roman and Medieval periods due to lead being found in Greenland ice cores.
"This new epoch emerged discontinuously through space and time during human history," Gabrielli said "In other words, our data challenge the concept of the onset of the Anthropocene as a synchronous global discontinuity in the global geological record."