Humans’ environmental rap sheet gets longer
Ice cores reveal air pollution 240 years before the Industrial Revolution
By Beth Mole
Long before factories, electricity and cars, humans found ways to besmirch blue skies.
Deep layers of ice from high in the Andes chronicle air pollution in South America starting around 1540, some 240 years before the Industrial Revolution. The likely source of the smog was silver mining spurred by Spanish conquistadores, scientists report February 9 in the Proceedings of the National Academy of Sciences.
Previous lake sediment records from South America had hinted at the ancient adulteration but were murky on the timing. Glacial ice cores, on the other hand, offer a year-by-year record of air pollution fallout dating back centuries.