Though known for its sub-zero climate, counter-intuitively the Arctic is the fastest-warming region on Earth. The Arctic’s northernmost environment, the Arctic Ocean, has warmed 0.75ºC over the last decade and by 3.3ºC since the 1880s, which is three times faster than the global average. The consequences of these changes are undeniable, destabilising, and far-reaching in oceanographic and ecological terms.

Indeed, the annual surveys of the Arctic Ocean’s rapidly reducing summer sea-ice cover – 4 million sq km over the last 40 years, representing a 40% reduction - have become the one of the most widely reported and visible indicators of the real-world consequences of human-driven global warming and climate change.

The Arctic Ocean (15 million sq km) is forecast to be 'ice-free' in Septembers by 2035-2067, ice-free meaning its summertime perennial sea-ice cover has been reduced to less than 1 million sq km (Nature, July 2023). Our planet will then have not only lost its northern hemisphere's unique floating ice-reef habitat, but one of its defining and globally-important surface geophysical features, and in a single generation - namely the white reflective heat-shield that was the ‘ice cap’ over the North Pole region.

More disturbingly still, the Arctic Ocean is forecast to potentially be an ice-free environment for up to 9 months of the year (May-January) within 80 years (Nature, July 2023). Simultaneously, these cold polar waters, which more readily dissolve CO2 from the atmosphere than temperate and tropical waters to form carbonic acid, are likely acidifying faster than any other ocean.

As previously impassable areas become accessible – initially the Northwest Passage and Northern Sea Route, and eventually the Central Arctic Ocean (CAO) – so the opportunity for vessels undertaking commercial exploration, exploitation and extraction increases. However, such activities introduce a host of negative impacts, experienced as stressors by the region’s biodiversity, which singularly and cumulatively reduce the resilience of the species and thus the functionality of their ecosystem services.

The stressors are generated by the every-day operation of every type of vessel including fishing, cargo-carrying, surveying, mining, cable/pipe-laying, and tourism cruisers. And the consequences of these stressors can have disturbing, dispersive, damaging and potentially deadly effects on the CAO’s ecosystem. And thus, these stressors translate into risks.

As the sea-ice cover recedes, this unique floating ice-reef habitat involving micro-organisms, plants and animals, and their associated life-supporting services, is likely already stressed, if not compromised.

At the heart of the argument to safeguard the Arctic Ocean’s biodiversity is the fundamental insight that the greater the diversity, abundance (ie complexity and connectivity) and health of biological life on Earth, the greater the capacity for ecosystems to develop and provide life-supporting ecosystem services like air purification, genetic resources, seafood production and carbon sequestration. Conversely, if complexity is reduced with species lost to extinction and/or the connectivity is reduced as the population of individual species falls, the more our Earth’s life-sustaining, self-regulating system is compromised.

The responses of the northern hemisphere’s oceans to greenhouse gas emissions may also result in the Arctic Ocean becoming the place-of-last-resort for marine species forced to head to the northern hemisphere’s coolest waters as their traditional waters to the south continue to heat up. Such a scenario would see the region providing a last-stop holding area, or biological refugium (or ‘Arctic Ark’) for non-native species, until global ocean warming is brought under control – likely over millennia due to ocean chemistry and geophysics.

Carefully-targeted conservation measures are now urgently needed to safeguard the sustainability of the Arctic Ocean’s biodiversity. The proposed measures, supported by scientific evidence, will seek to optimise the resilience and health of the region’s biodiversity within the wider context of globally sustainable development.