Polar ice is crucial to life as we know it – here's why

Standing at the top of a mountain in Antarctica can change the way we see the world. The more we look, we find that polar regions reveal how dramatically our planet can change and, at the same time, give us glimpses into our future. 

Bedrock rises through the ice in places, making for summit vistas that extend uninterrupted across the polar ice cap for hundreds of miles. But from where I stood during my expedition, there is a view inside the rocks that is every bit as awe inspiring as the drama of the landscape. Here, sediments were formed in tropical rivers and lakes 380 million years ago.

Among the grains in the rock lie fossilised remains of sharks and fish that are closely related to us in evolution. The disconnect between the forbidden regions of the poles today and the ancient lost worlds inside the rocks could not be more stark. The story of our planet is one of change, particularly at the poles. 

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The Arctic and Antarctica encompass only 8% of the total surface of the Earth but hold an outsized influence on our existence. Almost 70% of all the planet’s freshwater is frozen in ice. Antarctica alone contains enough ice that, if melted entirely, could raise global sea levels by nearly 50 metres. On land, permafrost in the polar regions holds 1,600 billion tons of carbon – roughly double that in the entire atmosphere today. Locked in the soils and ice of the poles are clues to our past, and things that will shape our planetary future. 

Every milestone of human evolution, from the origin of our species to the establishment of our social structures and technologies, arose during a time of ice at the poles. Freezing and thawing over millennia, the Arctic and Antarctica are like safes that hold our planet’s heirlooms. When polar regions melt, a vault is thrown open – ancient water, carbon, meteorites and microbial life spill into our world. 

The poles gain their importance through their special relationship with the sun. Because sunlight hits polar regions at a low angle, they receive far less solar energy than other parts of the planet. This makes them extremely sensitive to even small changes in temperature – like a meticulously balanced scale where the slightest touch can tip the system into a new state.

When these regions warm, the effects ripple throughout the globe, altering weather patterns, ocean currents, and ecosystems thousands of miles away. 

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The poles also serve as time capsules, preserving layers of history that help us understand our past and glimpse our future. Ice cores contain bubbles of ancient air that reveal how Earth’s atmosphere has changed over millennia. Valley walls hold rock layers that document billions of years of evolution.

Even the ice itself contains atoms that tell the story of how polar regions have grown and shrunk over millions of years. This geological record is invaluable for understanding how Earth’s climate has changed in the past and what might lie ahead. 

Polar ice is like an invisible hand that has sculpted our world and will shape our future. For millennia, our species has lived with land, coastlines, oceanic islands and sea levels defined by the amount of water locked in polar ice. Our political boundaries, trade routes, even agricultural belts are linked to feedbacks with polar ice.   

We have become ever more reliant on the health of these regions just at a time our activities are rapidly altering them. The Arctic is warming nearly four times faster than the global average, with some regions like the Barents Sea heating up seven times faster.

But this isn’t just about surface ice melting. The very ground beneath the Arctic is thawing, as permafrost that has been frozen for thousands of years begins to buckle and collapse. It isn’t a gradual process: in some places, 70 feet of river coastline can disappear in days. These changes affect us all: sea levels are estimated to rise as much as metre by the end of the century. 

Rising seas and changing coastlines are not the only effect of changes to the polar regions. The Arctic is also becoming a new frontier for geopolitical competition. As ice retreats, previously inaccessible areas are opening up for oil, gas, and mineral exploration, new trade routes, and access to fisheries.  Geological quirks in the sea floor mean that the region below the North Pole is becoming the site of competing territorial claims by Russia, Canada and Denmark, each seeking to extend their continental shelf rights. 

Polar regions are as crucial to Earth’s systems as organs are to a living body. Humanity’s encounters with the poles, from the experience of Inuit over millennia to the British, European and American explorers who followed them have found our own vulnerabilities – as well as our capacities for resilience, growth, and discovery – in the most remote landscapes on our planet. 

Ends of the Earth: Journeys to the Polar Regions in Search of Life, the Cosmos, and Our Future by Neil Shubin is out now (Oneworld Publications, £22). You can buy it from the Big Issue shop on bookshop.org, which helps to support Big Issue and independent bookshops.

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