The evidence preserved in the glacier provides a continuous record of climate and vegetation during major historical events.
Europe’s past prosperity and failures driven by climate change have been revealed using pollen, spores, and carbon particles that have been fossilized in glaciers for thousands of years. The first analysis of microfossils preserved in European glaciers revealed evidence of earlier-than-expected air pollution and the root cause of modern invasive species problems.
A new study examines pollen, spores, carbon and other pollutants frozen in the Colle Gnifetti Glacier on the Swiss-Italian border. Studies have found that changes in the composition of these microfossils are closely related to major events known in the climate, such as the Little Ice Age and mature volcanic eruptions.
This work was published in the “Geophysical Research Letters”, which published short, high-impact reports whose direct impact spanned all earth and space sciences.
The industrialization of European societies also clearly appeared in the microfossil record, and in some cases occurred earlier than expected. Pollen from imported non-native crops was discovered at least 100 years ago, and pollution caused by burning fossil fuels appeared in the 18th century, about 100 years earlier than expected.
Existing historical data, such as daily records or church records, record conditions during major events such as drought or famine. However, studying glacier data can help understand the climate and land use surrounding such events, providing them with uninterrupted background and evidence of large areas of land. Determining the timing of these events can help scientists better understand current climate change.
Sandra Brugger, a paleoecologist at the Nevada Desert Research Institute and the lead researcher of the study, said: “Previously available historical data, I think [source] does not have a comprehensive understanding of the environmental context.” But for the ice core, we can’t get the full picture until we start working with historians on this. You need the two sides of the coin.”
This new study analyzes two 82-meter and 75-meter-long ice cores extracted from the Colle Gnifetti glacier and frozen microfossils, which are the first two ice cores for the study of microfossils on the European continent. Similar studies have sampled ice cores in South America, Central Asia, and Greenland, but these areas lack the breadth of written historical records that can be directly correlated with continuous microfossil data in ice cores.
For centuries, wind, rain, and snow have brought microfossils from the European lowlands, the United Kingdom, and North Africa to exposed glaciers. The ice at this glacier site can be traced back tens of thousands of years. The height of Colle Gnifetti at an altitude of 4,450 meters means that the ice may never melt. This will mix the sample layers and cause records of chronological uncertainty.
John Birks, a paleoecologist at the University of Bergen, said: “In fact, they can pinpoint the relationship between what is happening on the continent and the climate record inherent in the ice.” A stronger way to develop this link between human civilization and change and climate, especially in the past thousand years or so, traditional pollen analysis is very weak.”
Evidence of pollution caused by the burning of fossil fuels also appeared in the time record earlier than expected. Researchers found evidence of early coal burning in the UK around 1780, long before the expected start of industrialization around 1850, which may have an impact on simulating global climate change.
The record also shows evidence of pollen from non-native European plants 100 years ago, showing the long-standing legacy of existing ecological problems caused by trade in invasive species that crossed the continent.