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What evidence shows that glaciers expanded during the Little Ice Age?

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Line graph showing estimated temperature variations from 1000 to 2000 CE for the Northern Hemisphere and central England, with three lines representing different data sources. The chart highlights the medieval warm period around 1100-1300 and the Little Ice Age from about 1500 to 1850, followed by a sharp temperature rise in the late 20th century. Temperature is shown as deviations from the 1961-1990 average. — Little Ice Age Estimates of temperature variations for the Northern Hemisphere and central England from 1000 to 2000 ce.

During the Little Ice Age (roughly 14th to mid-19th century), evidence for the expansion of mountain glaciers is found in several regions, including the European Alps, Alaska, New Zealand, and the southern Andes.1

Key evidence of this expansion includes:

Physical Encroachment: In Europe, Alpine glaciers advanced significantly beyond their previous and present limits, physically obliterating farms, churches, and villages in countries such as Switzerland and France.1
Proxy Records: Scientists utilize indirect evidence, known as proxy records, to reconstruct past climatic conditions. These include ice cores, lake sediment cores, and tree growth rings, which indicate periods of cooling that supported glacial growth.1
Historical Documentation: Records from the period document the environmental impacts of these advances, such as the expansion of sea ice in the North Atlantic, which isolated settlements in Greenland and Iceland as ice coverage increased dramatically.1
Geological Signatures: Glacial advances produce dynamic responses, such as changes in ice flow and the extension of glacier termini, which leave lasting physical evidence on the landscape.2