Fighting to save the planet in his shed on Gometra island

The draughty, weatherbeaten outbuilding is one of the few places on Gometra with a mobile phone reception.

So as fellow team members completed tasks south of the Border and beyond to create the Ocean Rebellion campaign, Roc Sandford set to work in his island shed, systematically identifying the gaps in their plan to save the world.

Dressed for the cold in his unheated office, he has spent the last five months contacting people of power, from industry leaders to celebrities, in a bid to prompt action over climate change – before it is too late.

Ocean Rebellion, the independent seafaring sister organisation to the global grassroots movement Extinction Rebellion, aims to speed up global change in international waters.

The group claims humans are creating a man-made climate emergency, devastating marine habitats through overfishing.

And they say that cruise liners are pumping out three times more climate pollution, per person per mile, than the equivalent flight. The campaigners fear that, without action, a global temperature increase averaging 4C will see billions of people wiped out, as much of the planet becomes uninhabitable.

Speaking as Ocean Rebellion was launched today, Mr Sandford said the masses had failed to grasp the reality of the death and destruction that will occur if the world does not change its ways.

He said: “It’s all science based – it’s just that society isn’t grasping it, it is like it is too big to understand. “What is going on at the moment is a triple emergency; a viral emergency, a climate emergency and a biodiversity emergency. The viral emergency is a complete tragedy but it’s not going to kill everyone... the climate emergency and the biodiversity emergency do have the capacity to kill everyone.

“The viral emergency is about protecting the old, because half the people who die are over 80, but who is shielding the young who are going to die of these other emergencies. No-one is shielding them. “It’s like a child sacrifice is happening.”

Gometra, off Mull, which routinely has only a handful of residents living there at any one time, has no electricity, no cars, no ferry and no school. It aims to be carbon neutral before 2025.

Mr Sandford said: “From my shed I have been speaking to all kinds of people, people who are household names, people in industry, people involved in the civil service and legislation, trying to catalyse people of power.

“I am trying to bring people out of denial, so that people feel this as a real thing.”

Ocean Rebellion campaigners are engaging with high seas stakeholders to try and address collapses in biodiversity due to over-fishing, human-caused climate change, deep sea mining and other marine emergencies.

While acknowledging that the public are appalled by the devastation plastics have caused to oceans, they say habitats all over the world remain vulnerable, with a third of marine mammals now facing extinction.

Pressing for action to reverse the drivers of ocean warming and sea level rise by 2025, the campaigners have also stressed that this kind of climate pollution is threatening almost all ecosystems.

Mr Sandford, an avid environmentalist, gave up his car years ago and travels around by bike in his bid to lower his carbon footstep.

He says everyone can do their bit to address climate change by examining factors such as the impact of the way they travel, the food they eat and their reliance on central heating.

And he said that a lot of work would have to be done to secure improvements.

The father of four said of his own family: “We have miles to go, but we are drastically trying to decarbonise our lives. I am now experimenting with low carbon cooking, basically boiling stuff and then putting it in a thermos flask to cook.”

He added: “I am looking at, where is the carbon in my life. I have got to do better, we all have to do better.”