An expedition team has set sail from Plymouth, Devon, on a 5,000-mile carbon emission-free round-trip to the Greenland ice cap.
The team, which left Mount Batten Marina on Sunday, will rely on sail, solar and man power.
Former cancer patient Raoul Surcouf and his teammates hope to raise money for the charity Teenage Cancer Trust.
The expedition will be followed by up to 40 schools across the UK to promote climate change awareness.
The organisation behind the trek, Carbon Neutral Expeditions (CNE), was set up by Mr Surcouf and teammate Richard Spink, who met on an exploration to the Geomagnetic North Pole.
Mr Surcouf said: "The expedition will hopefully show how it is possible to explore some of the most beautiful places on Earth without contributing to their destruction."
Whilst many explorers fly to Greenland, the CNE team will sail more than 2,000 miles across the North Atlantic with skipper Ben Stoddart to avoid the environmental costs of air travel.
Raoul Surcouf has recovered from Hodgkin's disease, a form of cancer
Once they have reached Port Nuuk, Greenland, the two men will set out on a 580-mile trek to the highest point of the ice cap, and then back to the boat for the sail home.
CNE said: "Return journeys are in the true spirit of expeditions, and essential if this is to be carbon neutral."
During the expedition, the team will relay their progress via the internet to an audience of about 25,000 pupils a week.
Making a difference
As well as educating children, it is hoped the team's endeavour will also help younger people who have been diagnosed with cancer.
Mr Surcouf, 40, was diagnosed with Hodgkin's Disease in 1986.
He said: "I wasn't lucky enough to be treated on a Teenage Cancer Trust unit when I had cancer.
"By organising this expedition, we hope to raise as much money as possible for Teenage Cancer Trust.
"Having access to a unit which has staff that understand what you need as a teenager and the chance to meet and just hang out with other young people would have made such a difference to my experience."
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.