Swimming towards a coal ship

Around midnight three of my colleagues eased themselves off one of the Greenpeace inflatable speedboats and into the cold water of the river Medway in Kent.

It's difficult to imagine what must be going through your mind in that situation - in the dark, in the cold water, with the looming lights of a large ship getting closer. But however difficult to imagine it is, it must have been even more difficult to do, because Cathy, Emma and Hannah knew that they were swimming out into the channel to block a coal freighter carrying twenty thousand tonnes of coal from docking at the Kingsnorth jetty.

[ Follow the action on twitter: @greenpeaceuk ]

Video: Watch the video highlights from the ship boarding and an interview with volunteer Sarah Shoraka from the mast of the E.on ship.

As they made their swim - on one of the shortest nights of the year - more Greenpeace volunteers flagged the ship down with flares and banners, pulled alongside and clambering up the steep metal sides, across the deck, and on up the mast and funnel. They secured themselves in place and waited for the calls from the morning news shows.

Looking down from the mast of the ship.

The funnel carries the logo of E.ON, the German energy company who operate the power station at Kingsnorth. E.ON would like to build another coal-fired power station on the site, and the place should be a building site by now. But the plans have been opposed by environmental experts and campaigners, met with indecision from  government, and been delayed again and again.

Despite recent government assurances that any new coal fired power stations will capture the carbon they release into the atmosphere, the devil in the detail means that a new plant at Kingsnorth would still pump three quarters of its carbon into the atmosphere - six million tonnes of CO2 a year, a phenomenal amount.

Does this explain why someone would voluntarily swim into the path of a coal ship? My colleague Emma, one of the swimmers who lives in nearby Whitstable, explained what was going through her mind before the action: "There's no way we can stop climate change if power companies are allowed to keep on burning so much coal. I'm terrified by the scale of the problem my children will have to deal with. We have to give the next generation a chance of beating global warming, and that's why I'm putting my body in the way of that ship."

In terms of greenhouse gases, coal is the dirtiest fuel there is. Coal plants lead to carbon emissions which drive climate change - which threatens people and property around the world from increased risk of flooding, drought, water shortage and extreme weather events. We want to see strong government leadership on energy policy in the run up to the Copenhagen climate summit in December. All of this is why we intervene to stop dirty coal power from becoming the future of Britain's energy.

But while this might explain why Greenpeace campaigns on coal, I'm not sure if it can explain how you put yourself in a place where you're floating in front of an oncoming ship because you've realise that a time comes when this is what the reality of coal's role in driving climate change demands of you.