New satellite images released by NASA show there has also been a dramatic decline in the amount of perennial sea ice in the Arctic.

However the space agency says there has been a slight recovery in the amount of seasonal ice covering the Arctic.

Last summer, the perennial sea ice, the oldest and thickest kind, melted by a record amount, allowing ships to navigate the North-West Passage connecting the Atlantic to the Pacific.

A scientist from the US Naval Academy, Ted Maksym, says it is only a matter of time before there is no Arctic ice left at all.

"For the first time, as far as we're aware, there is no thick, old ice at the North Pole," he said.

"So again, if we have another warm year like we did last year, it could be for the first time in recorded history, an ice-free North Pole."