The full story, as told in the UK Guardian can be found at: https://www.theguardian.com/environment/2017/apr/16/arctic-ice-cores-melt-university-alberta-canada
and briefly it tells of an equipment failure at a storage facility for ice cores that had been extracted from the polar ice cap in various locations.
But note, that the layers of ice evident in the cores covered a period of 22,000 years. And from the christian/JW perspective, that's impossible, for the bible story of the flood (verified by jesus and sundry other biblical writers) maintains that 4000+ years ago, the ice caps would have melted during the period when the earth was covered by the divinely caused deluge.
Yet jws and many other others including muslims, jews, and sundry christians believe that their fanciful religious fantasy is true in the face of factual evidence to the contrary