Melting poles: Unprecedented levels of sea ice loss threatens global climate balance

Internet outrage erupted recently when a manipulated image depicted a flourishing flower field in Antarctica, not far from its icebergs. However, the unprecedented warming of these regions and a fivefold increase in flora suggest that there's no need to create such pictures anymore. The dwindling ice coverage in both polar regions is now an additional cause for concern.

NASA and the National Snow and Ice Data Center (NSIDC) define sea ice extent as areas where ice covers at least 15% of the ocean. This phenomenon's extent fluctuates with seasonal temperature changes, and satellites continuously monitor it. Sea ice plays a crucial role in maintaining Earth's temperature by reflecting a significant amount of the Sun's radiation. Losing sea ice cover leads to the oceans taking its place and absorbing 90% of the Sun's heat, which ultimately contributes to atmospheric warming and accelerates global climate change.

Given these critical factors, minimising sea ice melt is imperative, especially in today's challenging climate. Unfortunately, recent trends are not promising. Researchers reported that Antarctic sea ice reached its lowest maximum extent on September 10, and Arctic sea ice likely reached its annual minimum extent on September 19, both events occurring during the ice's refreezing cycle in a colder month.

To provide perspective, the Arctic lost enough sea ice between March and September this year to cover an area more than three times the size of India, totaling approximately 10.23 million square kilometres. September's extent of 4.23 million square kilometres is nearly 2 million square kilometres below the 1981-2010 average.

Antarctica's situation, while somewhat better, is still troubling. The region reached only 17 million square kilometres of sea ice at its peak, losing ice equivalent to the combined size of Rajasthan, Madhya Pradesh, and Maharashtra, and one million square kilometres less than the previous record-low in 1986. According to 1981-2010 data, the region should have had at least 18.71 million square kilometres of winter ice.

Walt Meier from the NSIDC remarked, "It’s a record-breaking low in the Antarctic. Sea ice growth appears low around nearly the whole continent as opposed to any one region.”

However, the extent of sea ice is not the sole concern; thickness and density matter to withstand the Sun's persistent radiation. Meier explains that there is more open ice than before and an increase in loose, lower concentration ice, even near the North Pole, which used to be solid sheets of ice during summer. This trend has become more frequent in recent years.

With the melting season starting earlier and lasting longer, the Arctic and Antarctica have less time to accumulate high-quality sea ice. Freeze-up is happening about a week later per decade on average, and it's already occurring one month later than in 1979.

Several factors contribute to these disheartening polar records, with ocean heat being a significant one. Melting ice exposes more of the ocean's surface to solar energy, resulting in greater ocean warming, which, in turn, exacerbates ice melting. El Niño and shifting wind patterns also play crucial roles in hindering winter ice growth and worsening summer ice melt.