The Arctic and the Antarctic are, appropriately, polar opposites. The first is ocean surrounded by continents, the second continent surrounded by ocean. In one, there are communities of indigenous people and migrants; in the other, only transient, for a season or two. Nuclear-armed powers have faced off in the Arctic since the Cold War; that same conflict created a regime of peaceful scientific cooperation for Antarctica that is more utopian in its conception than any other agreement in the history of diplomacy. The north has the majesty of polar bears, the south has the compassion of penguins. Both are united in facing profound upheaval due to global warming. But compared with the changes affecting the Arctic, those threatening Antarctica are vastly underestimated.
Partly this lack of attention is due to Antarctica’s remoteness; the biggest base there, the US’ McMurdo, is nearly 4,000km from the nearest city (Christchurch in New Zealand). Most of the people who visit are scientists, adventurers and support staff. Partly, there is a kind of stability. Change in Antarctica is not like in Alaska, where melting permafrost causes roads to break up and buildings to collapse; or Siberia, where smoke from burning tundra colours the sky and burns the lungs. Indeed, for a long time scientists have regarded Antarctica as relatively stable, at least in the short to medium term. Yes, its ice sheets hold enough water to cause seas to rise by 60 metres – but any collapse would take centuries.
It seems that was negligence. Earth’s largest refrigerator, as we reported in this week’s Science and Technology section, is showing dangerous signs of a massive melt, which will also have an impact on the rest of the planet. Extreme events such as the disappearance of an area of ​​sea ice the size of Greenland during last year’s Australian winter are a symptom of underlying instability. Glaciologists are talking of a “regime change”. Part of one of the vast ice sheets that covers 98% of the continent is sliding towards the sea.
The transfer of water from Antarctica’s continental base to the Southern Ocean contributed only 4% of global sea-level rise 20 years ago. Today it accounts for 12%, and will continue to grow in the coming decades. This effect has an underestimated consequence. As Antarctica melts, the gravitational attraction of its shrinking ice on neighbouring seas weakens. This causes sea levels to rise even faster elsewhere. Sea-level rise originating from Antarctica will affect Australia and Oceania, but it will also disproportionately affect North America.
Melting ice sheets do more than raise sea levels. They also trigger changes in atmospheric circulation that extend to the equator and beyond, altering weather in the Sahel and Amazonia. And the Southern Ocean is one of the world’s biggest carbon sinks, responsible for absorbing 40% of all the climate-changing carbon dioxide absorbed by the oceans each year. If it warms, it will absorb less—an effect that could be exacerbated when trillions of tons of fresh water flowing off the great frozen south alter ocean currents.
Despite all this, some countries are cutting their budgets for Antarctica research. This defies logic. Measurement and modelling of ice sheets lags far behind studies of the atmosphere and ocean currents; this needs to be fixed quickly if the implications of a worsening situation are to be properly understood and planned for.
The ongoing debate over what most needs to be done and how best to cooperate to get it done should motivate the 56 countries that have signed the Antarctic Treaty. They may not be able to protect the Antarctic environment, a duty to which the Treaty’s Environmental Protocol commits them. They could at least increase their efforts to learn what the changes being made on the empty continent in their charge mean for the rest of the world.
© 2024, The Economist Newspaper Limited. All rights reserved. From The Economist, published under licence. Original content can be found at www.economist.com.
