The amount of sea ice that persists throughout the summer also affects how thick ice will grow in the Arctic in the winter. Ice that builds on an existing layer of ice can grow thicker than ice that grows seasonally from scratch. Summer sea ice in the Arctic naturally shrinks in the summer. According to the National Snow and Ice Data Centre (NSIDC), Arctic summer sea ice dwindled to 4.23 million square kilometres on Sept. 19 — the sixth lowest extent on a 45-year record. ‘Smooth sailing’ on Northwest Passage routeDwindling summer sea ice is also changing how ships can travel through the Arctic.

Source: CBC News October 19, 2023 15:23 UTC