These mounds are not new, but they are multiplying due to climate change and are spreading into cities, threatening some ...

is very big in scientific terms because the permafrost does not freeze as deeply as usual," said Alexander Makarov, director of the Arctic and Antarctic Research Institute in Saint Petersburg.

"A difference of one or two degrees Celsius, even if the temperatures are still negative, is very big in scientific terms because the permafrost does not freeze as deeply as usual," said Alexander ...