Nick Miles

Now, Esme, this potential solution uses an intriguing combination of substances, doesn't it?

Now, Esme, this potential solution uses an intriguing combination of substances, doesn't it?

And it effectively works as a filter. Is it 100% effective?

And it effectively works as a filter. Is it 100% effective?

And it effectively works as a filter. Is it 100% effective?

You were saying that these substances are easy to get hold of. So I imagine the idea of being able to scale this up is a real possibility.

You were saying that these substances are easy to get hold of. So I imagine the idea of being able to scale this up is a real possibility.

You were saying that these substances are easy to get hold of. So I imagine the idea of being able to scale this up is a real possibility.

Well, this is La Fontaine Jazz Club. It's the oldest in town. It's often described as the best jazz club on this side of the Atlantic. It's a little corner of America here in Copenhagen. And we've come to this place at a time where, once again, President Trump is saying he wants a not-so-little chunk of Denmark in the form of Greenland, the biggest island in the world.

Well, this is La Fontaine Jazz Club. It's the oldest in town. It's often described as the best jazz club on this side of the Atlantic. It's a little corner of America here in Copenhagen. And we've come to this place at a time where, once again, President Trump is saying he wants a not-so-little chunk of Denmark in the form of Greenland, the biggest island in the world.

Music student Lucas is here with friends Molly and first Clara.

Music student Lucas is here with friends Molly and first Clara.

This is the changing of the guard outside the Royal Palace in the heart of Copenhagen. At a time, of course, when there's been a big change in Washington, D.C., President Trump now fundamentally changing some of the relationships with America's closest allies, countries that have stood shoulder to shoulder with America for decades. And, of course, Denmark is in that group.

This is the changing of the guard outside the Royal Palace in the heart of Copenhagen. At a time, of course, when there's been a big change in Washington, D.C., President Trump now fundamentally changing some of the relationships with America's closest allies, countries that have stood shoulder to shoulder with America for decades. And, of course, Denmark is in that group.

Hans-Tino Hansen runs Risk Intelligence. They give advice on threats around the world. President Trump claims U.S. control of Greenland is an absolute necessity for international security.

Hans-Tino Hansen runs Risk Intelligence. They give advice on threats around the world. President Trump claims U.S. control of Greenland is an absolute necessity for international security.

Still, Denmark has said it will spend an extra $2 billion on defence, including in the Arctic. And Hans believes security there can be bolstered without an American takeover, but with deals that restore the scope of US influence.

Still, Denmark has said it will spend an extra $2 billion on defence, including in the Arctic. And Hans believes security there can be bolstered without an American takeover, but with deals that restore the scope of US influence.

With President Trump eyeing up Greenland's mineral wealth, we've come to meet Professor Minik Rösching, one of the world's leading geologists. Professor Roshing warns that the vastness of his homeland and the lack of infrastructure are just two elements of why Greenland may not be the cash point some Americans may hope for.

With President Trump eyeing up Greenland's mineral wealth, we've come to meet Professor Minik Rösching, one of the world's leading geologists. Professor Roshing warns that the vastness of his homeland and the lack of infrastructure are just two elements of why Greenland may not be the cash point some Americans may hope for.