GEOFF BENNETT: When you think of fresh produce and fields of grain, the Arctic may not spring to mind, but just 800 miles from the North Pole, the Global Seed Vault holds emergency stockpiles of most of the world's crops.

It provides scientists with the tools they need to breed plants able to cope with a changing world.

With global warming and an ever-growing population, those who run the vault in Svalbard, Norway, say its presence is more important than ever.

We sent special correspondent John Bevir to the northernmost settlement on Earth to find out more about the future of food.

JOHN BEVIR: It's known by some as the doomsday vault and often referred to as the ultimate insurance policy, buried deep in the side of a mountain, itself in the Arctic Circle, the most diverse collection of food crop seeds in the world.

INNOCENT DOSSOU AMINON, Gene Bank Director: It's very important.

JOHN BEVIR: Innocent Dossou Aminon runs the gene bank in Benin.

He has made the 5,000-mile journey from West Africa to the Norwegian archipelago of Svalbard.

With him, he's brought his country's first seed deposits.

INNOCENT DOSSOU AMINON: If anything happened in our place, we can come back and request some seeds to regenerate for the farmers.

JOHN BEVIR: Maize, rice and soybeans are some of the crops being added, and they're in good company.

There are regular deposits from gene banks in every corner of the globe.

The collection now stands just short of 1.2 million varieties in total.

They're scanned to check that nothing unwanted ends up in the vault.

Apart from any doomsday scenarios, the vault acts as insurance against more day-to-day issues like power outages in developing countries.

INNOCENT DOSSOU AMINON: It's important to be here to prevent any catastrophe in future.

We keep the seeds in a freezer.

And the lights go and power comes back.

It changed the inside temperature of the freezer.

And this affects the germination of the seeds.

And then we lost a lot of our accessions.

It's important to duplicate, so that, if anything happens to what we are conserving in our country, we can get it back from the vault easily to regenerate.

JOHN BEVIR: The average temperature in Benin at this time of year is 89 degrees.

That, by chance, is 89 degrees warmer than here.

Although the vault is kept artificially chilled, Svalbard's permafrost acts as a good backup.

And it was that permafrost that started this whole project.

In one of Svalbard's abandoned coal mines, we get a rare chance to see the original, primitive vault.

In 1984, the Nordic gene bank started an experiment as unique as the location.

Michael Lyngkjaer is using the work done by his predecessors to learn more about preserving crops and all that comes with them.

MICHAEL LYNGKJAER, Research Team Leader, NordGen: Every fifth year, the -- one box is taken out, opened, and then the seeds will be tested for viability.

It will be tested for if there have been any changes.

And with all seeds, there's also coming some microorganisms which are following the seed naturally.

Some of these ones are pathogenic.

So, we also look at how the pathogenic fungi, they will survive.

So we will be, by conserving the seeds, also conserve the type of diseases which was present the seeds were put in here.

JOHN BEVIR: This experiment in the mine has another 61 years to run.

The world, and especially the Arctic, will be a very different place then.

Svalbard's prosperity was forged out of these mines, but, of course, the irony is that the impact of burning this coal is what threatens Svalbard's very future.

You used to be able to walk over the fjord here in winter, but the sea ice is long gone.

Now you would need a boat.

The Arctic is warming faster than anywhere else on Earth.

Stefan Schmitz runs the Crop Trust, a nonprofit organization dedicated to improving global food security.

He says a warming world is a key reason to preserve crop diversity.

STEFAN SCHMITZ, Executive Director, Crop Trust: Under climate change, that means rougher climates, higher temperatures, longer droughts, more flooding, new pests and diseases.

And our food, our crops need to be resilient.

They need to cope with these changing circumstances.

And, therefore, plant breeders need all those varieties.

Take the genetic varieties out of them, mix them, crossbreed them to make sure the new varieties are fit for the future.

JOHN BEVIR: We live in a world of mass farming, where fewer staples are being grown.

Of an estimated 6,000 plant species humans have eaten, just nine are now common, and three, wheat, rice and maize, provide around half of all the calories consumed globally.

This vault aims to be entirely apolitical, and operates on the belief that diverse genetic resources are an asset for humanity.

There are more than 1,700 gene banks in the world, all trying to improve what we eat.

This flour contains Oland's wheat, a once long-forgotten Swedish variety.

In the 1990s, a plant breeder took some seeds from the Nordic gene bank in the hope of reintroducing this wheat.

He quickly worked out that, although it made fantastic bread, the yield was quite low, and it grew so tall that it was difficult to harvest.

But with that height comes incredibly deep roots, and it turns out that Oland's wheat is drought-tolerant.

Bread containing that wheat is now found in high-end bakeries across the world.

But a lot of the work done in gene banks is aimed at providing food security for at-risk populations.

The Global Seed Vault ensures those seed samples are always available.

The remoteness of the vault also helps protect it from other manmade problems.

A Syrian gene bank destroyed by civil war withdrew its deposits from the vault in 2015, regrew them, and returned new seeds in their place.

After 15 years, the number of seed varieties and the countries putting them in continues to grow.

And there are stark warnings that the genetic diversity stored within this vault will be needed to feed an ever increasing population in an increasingly harsh environment.

For the "PBS NewsHour," I'm John Bevir in Svalbard, deep in the Arctic Circle.