I know someone that doubts this.
He says:
“During this same 30 year period, the number of breeding pairs of Adélie penguins has fallen from 32,000 to 11,000. This is probably not the result of things remaining the same, or an increased number of penguin hunters. It might be because they don’t have as much ice as they used to.”
It might be. It might not be. It might be BS for that matter. Most animal populations fluctuate over time. Pretty slim pickings on which to base a catastrophic scenario for the whole world.