Scientists in Greenland have told Al Jazeera that an ice sheet that covers 80 per cent of the territory is shrinking much faster than expected.

In recent months, unusually large chunks of ice have broken off its glaciers - one of them four times the size of the US city of Manhattan.

Some experts are worried this increasing rate of melting could raise sea levels across the globe.

Nazanine Moshiri reports from Illulisat in Western Greenland.