The millennia-long history of glaciers and the influence of the sun and humans

The history of glaciers is a fascinating testament to the dynamics of our planet and traces the changes in Earth’s climate over thousands of years. Influenced by countless factors, one of the most significant has always been the sun, the central source of Earth’s heat. Join us on a journey through time to understand the intertwined history of the sun and these icy monoliths.

The glaciers as we know them today formed during the last ice age, which took place approximately 110,000 to 12,000 years ago. During this period, solar radiation on Earth decreased, leading to cooler global temperatures. These conditions facilitated the growth of extensive ice sheets across the Northern Hemisphere, covering regions from the Alps to the plains of North America. As the Earth received more sunlight, temperatures rose, the ice retreated, and left behind the impressive glacial landscapes we see today.

Even after the Ice Age, the interplay between the sun, the Earth’s climate, and glaciers continued. During cooler periods, such as the Little Ice Age from about 1300 to 1850, reduced solar activity led to the advance of glaciers. Conversely, during warmer periods, increased solar radiation contributed to the melting of glaciers, reshaping landscapes and feeding rivers and lakes. Over thousands of years, glaciers have served as the Earth’s historians; their advance and retreat document our planet’s climatic journey.

However, in line with the significant influence of the sun, the history of glaciers has taken a disturbing turn over the past hundred years. Human-induced global warming has led to an unprecedented, accelerated rate of glacial retreat. This abrupt shift in the millennia-old story of glaciers is a cause for global concern.

Today, glaciers are a visible, tangible indicator of climate change. Their steady retreat is clear evidence of the urgency of the situation and sounds an alarm that is impossible to ignore. Recognizing the history of glaciers, their relationship to the sun, and the deviation from current trends underscores the magnitude of the impending crisis. The rapid melting we are witnessing today is not just another phase in their long history, but a cry for help from the Earth itself.

Many thanks to Julien Seguinot for this animation. He is a geoscientist with a passion for glacial landscapes and currently works in the Department of Biosciences at the University of Bergen.