Short answers, pulled from the story.
Arctic sea ice has declined by more than 50% since satellite records began in 1979. The decline rate is approximately 4.7% per decade, and the rate of ice loss has risen by 57% since the 1990s.
The IPCC Sixth Assessment Report (2021) concluded with high confidence that the Arctic Ocean will likely drop below 1 million km2 of sea ice in at least some Septembers before 2050 under all emission scenarios. Climate model estimates for a first ice-free September range from the 2030s to the 2050s depending on the emissions pathway used.
The record low Arctic sea ice minimum was recorded in September 2012 at 1.31 million square miles (3.387 million km2). This replaced the previous record set on the 18th of September 2007, when the extent was 1.61 million square miles (4.16 million km2).
Arctic sea ice reflects sunlight back into space; when it melts, dark ocean water absorbs more heat, driving further warming in what is called ice albedo feedback. Arctic ice decline between 1979 and 2011 is estimated to have produced radiative forcing equivalent to roughly a quarter of all greenhouse gas emissions over that same period, or about 10% of the cumulative increase since the Industrial Revolution.
Arctic shipping transits grew from zero in 1979 to 400-500 crossings along the Bering Strait and more than 40 along the Northern Sea Route by 2013. In August 2017, the first ship traversed the Northern Sea Route without icebreakers. A 2016 Copenhagen Business School report found that large-scale trans-Arctic shipping could become economically viable by 2040.
Polar bears have less time each year to hunt their preferred prey of seal pups on sea ice because the ice melts earlier in spring and freezes later in autumn. They are turning to less nutritious alternative food sources on land, leading to reduced body size and lower reproduction rates. Approximately 900 bears inhabit the Arctic National Wildlife Refuge conservation area.