State of the Planet

News from the Columbia Climate School

Glaciers Preserve Our History. We Must Defend Them.

person standing near crevasse in greenland ice sheet
Photo: Marco Tedesco

One of the questions I often get asked lately is about how COVID-19 will impact our planet’s glaciers. There is no definitive answer yet. But we do know a variety of ways that the pandemic could influence glaciers.

The reduction in the concentration of carbon dioxide in the atmosphere observed in the past months could lead to a decrease in the melting of the ice, but only if this reduction occurs on a large scale and over the long term. In fact, although many of the production and commercial activities responsible for CO2 emissions have been interrupted in different areas of our planet, the global concentration continues to increase at an exponential rate. Furthermore, even if we were to shut down all sources of CO2 emissions, the warming effects of the carbon dioxide accumulated in the atmosphere would continue to be felt for decades.

In addition, the reduction of atmospheric pollutants favors the increase of solar radiation that reaches the surface of our planet and, consequently, the melting of ice. However, how much of the solar energy will actually be absorbed (and therefore contribute to the melting) depends on the so-called “albedo,” which quantifies the ice’s ability to reflect or absorb solar radiation. Albedo, in turn, depends on how much snow has accumulated during the winter, on the accumulation of dust and pollutants and other factors.

This year, most scientific expeditions have been and will be canceled due to the pandemic, making it even more difficult to know what is actually happening on the glaciers.

On the other hand, one thing is certain: the pandemic that is affecting our society will be registered in the snow and ice that is forming on our planet. “These data will be preserved in ice,” said Lonnie Thompson, professor of earth sciences at Ohio State University, “and this means that in 100 or 200 years, that ice will show all that is in the atmosphere at the moment and will tell future generations what is happening now. ”

Snow and ice trap whatever is in the atmosphere, chemicals and minerals, but also bacteria, viruses and other organic materials. Ice cores show past changes, like a time machine: it is possible to identify the beginning of the Industrial Revolution in the late 1700s; the time when humans began adding lead to gasoline, but also evidence of the Black Death, a pandemic in the mid-1300s that remains the deadliest in human history. Likely the same is happening during these months, leaving a signature of the current pandemic in the ice cores.

One day, our children and future generations will dig into the ice and find clues to what is happening today to our planet and our society. Obviously, this assumes that glaciers will continue to exist in the future. This, unfortunately, is not obvious. The game isn’t over yet, but we don’t have much time left.

Adapted and translated from an article originally published in La Repubblica 

Marco Tedesco is a research professor at Columbia University’s Lamont-Doherty Earth Observatory.

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