In this article from the New York Times, the author admits that the causes of warming are debated:
But the thaw itself is already causing widespread anxiety. In Russia,
20 percent of which lies above the Arctic Circle, melting of the
permafrost threatens the foundations of homes, factories, pipelines. While the primary causes are debated, the effect is an engineering
nightmare no one anticipated when the towns were built, in Stalin’s
time.
Will wonders never cease?
