The Arctic seed vault had to deal with melting permafrost last winter

No seeds lost, but the entrance is being waterproofed after surprise flooding.

Scott K. Johnson

In Arctic Svalbard, there is a vault that might sound like a sci-fi plot device. Completed in 2008, the Global Seed Vault is a remote archive for safeguarding seeds for thousands of crop varieties. If anything dramatic should happen elsewhere around the world, we want these seeds to be there.
The vault consists of a giant freezer room bored into a mountain, protected by the bedrock around it and the permafrost above it. But according to a report in The Guardian, the vault experienced an unhappy surprise recently—melting permafrost in winter.
The Arctic just experienced its second-warmest winter on record (surpassed only by 2016), and Svalbard saw remarkable temperatures and even rain. In fact, Svalbard averaged more than 4 °C above even the 2004-2013 average.
As a result, meltwater trickled into the seed vault’s entrance tunnel before refreezing. The freezer room itself was safe, but the ice in the tunnel had to be chipped out. Hege Njaa Aschim, a spokesperson for the Norwegian government, told The Guardian, “It was supposed to [operate] without the help of humans, but now we are watching the seed vault 24 hours a day.”
Whether or not these conditions become common as the Arctic warms, precautions are being taken to avoid a repeat of this event. Precautions include waterproofing improvements for the entrance tunnel and drainage channels to divert meltwater. It might take a little more than sticking a freezer inside an Arctic mountain to keep these seeds cold and safe, it seems.