A different perspective:
"Björnsson describes how Ok shrank rapidly during the 20th century, as shown by its area on various maps: 38 sq. Km. in 1901, 15 in 1910, 5 in 1945, and under one Km. in 2016. Most of this was before anthropogenic warming became the dominant cause of warming. [...] If Ok died during the Medieval Warm Period, it was born again during the Little Ice Age. It may have lived and died countless times during its long life. Its latest death is another example of weather converted into propaganda."