A UK mission to sail the Arctic’s Northeast and Northwest Passages in a single season has succeeded – but sadly for all of us, it’s no cause to uncork the bubbly. Adventurer David Hempleman-Adams led his team into uncharted territory to highlight the disturbing disappearance of the region’s sea ice, which had previously made the passages impenetrable to mariners.

The yacht Northabout left Bristol, England, in June as part of a project called the Polar Ocean Challenge, which aimed to draw attention to the devastating effects of global warming on the Arctic. The Polar Ocean Challenge told the BBC that the success of their mission confirmed recent reports that Arctic sea ice is at the second-lowest extent ever recorded by satellites. “It’s real. We’ve been there,” they said.

The decline in the ice highlighted by Hempleman-Adams and his team was thrown into even sharper focus by an astonishing discovery made last week. The wreck of the HMS Terror, the long-lost ship of the 19th-century British explorer John Franklin, was found at the bottom of an Arctic bay in September.

The Terror, along with Franklin’s flagship the HMS Erebus, was abandoned in 1848 after both ships became stuck in heavy sea ice during an attempt to complete the Northwest Passage. 129 men – the entire party – lost their lives on the mission.

Northabout completed the Northwest Passage in just 14 days. The passage was almost totally free of ice.

“Whilst we are all delighted to have succeeded, it is extremely worrying to see this lack of ice so starkly”, Hempleman-Adams said.

Northabout will now sail south along the west coast of Greenland before striking for the UK and home across the north Atlantic. It is expected to be back in Bristol by October.

The expedition has provided another stark reminder of the terrifying effects of manmade climate change on the Earth. But apparently the lack of ice means commercial ships can start using the passages as trading routes, so, you know, there’s that.