The historical development of ice nucleating particle concentrations (N_INP) is still unknown. Here, we present for the first time N_INP from the past 500 years at two Arctic sites derived from ice core samples. The samples originate from the EUROCORE ice core (Summit, Central Greenland) and from the Lomo09 ice core (Lomonosovfonna, Svalbard). No long‐term trend is obvious in the measured samples, and the overall range of N_INP is comparable to present‐day observations. We observe that the short‐term variations in N_INP is larger than the long‐term variability, but neither anthropogenic pollution nor volcanic eruptions seem to have influenced N_INP in the measured temperature range. Shape and onset temperature of several INP spectra suggest that INP of biogenic origin contributed to the Arctic INP population throughout the past.

Ancient texts and archaeological evidence indicate substantial lead exposure during antiquity that potentially impacted human health. Although lead exposure routes were many and included the use of glazed tablewares, paints, cosmetics, and even intentional ingestion, the most significant for the nonelite, rural majority of the population may have been through background air pollution from mining and smelting of silver and lead ores that underpinned the Roman economy. Here, we determined potential health effects of this air pollution using Arctic ice core measurements of Roman-era lead pollution, atmospheric modeling, and modern epidemiology-based relationships between air concentrations, blood lead levels (BLLs), and cognitive decline. Findings suggest air lead concentrations exceeded 150 ng/m ³ near metallurgical emission sources, with average enhancements of >1.0 ng/m ³ over Europe during the Pax Romana apogee of the Roman Empire. The result was blood lead enhancements in young children of about 2.4 µg/dl above an estimated Neolithic background of 1.0 µg/dl, leading to widespread cognitive decline including a 2.5-to-3 point reduction in intelligence quotient throughout the Roman Empire.

Information about past ecosystem dynamics and human activities is stored in the ice of Colle Gnifetti glacier in the Swiss Alps. Adverse climatic intervals incurred crop failures and famines and triggered reestablishment of forest vegetation but also societal resilience through innovation. Historical documents and lake sediments record these changes at local—regional scales but often struggle to comprehensively document continental‐scale impacts on ecosystems. Here, we provide unique multiproxy evidence of broad‐scale ecosystem, land use, and climate dynamics over the past millennium from a Colle Gnifetti microfossil and oxygen isotope record. Microfossil data indicate that before 1750 CE forests and fallow land rapidly replaced crop cultivation during historically documented societal crises caused by climate shifts and epidemics. Subsequently, with technology and the introduction of more resilient crops, European societies adapted to the Little Ice Age cold period, but resource overexploitation and industrialization led to new regional to global‐scale environmental challenges.