The former antiapartheid activist who now heads Greenpeace, Kumi Naidoo, spent his weekend in a Greenland jail after a headline-grabbing dash onto an Arctic sea oil rig. Naidoo, who is from Chatsworth in Durban, dodged a Danish war-ship and hauled himself up an 80 ft ladder attached to one of the rig’s legs while being pummeled by freezing water cannons fired from above.

“People may wonder why I, as an African, care about what is happening in the Arctic,” said Naidoo, before hopping into his speedboat, “but scientists say the unprecedented warming up here could have grave knock-on consequences for vulnerable people across the world.”

Once on board the rig, Naidoo attempted to hand over a 50,000 name-long petition calling for the Scottish firm Cairn – which operates the Leiv Eiriksson rig – to stop drilling in the Arctic, and requested a copy of their oil-spill response plan. (He believes they don’t have one, because it wouldn’t be possible to contain such a catastrophe if it happened in the Arctic).

The Greenland penitentiary system will be a new one for Naidoo, who was regularly arrested by South African police under apartheid. The former hunger-striker sounded upbeat about prison rations in a letter sent to friends and family at Durban University of Technology:

“Actually having three meals a day which with my schedule is normally rare as you know… and on regular times too. Just missing spicy food though,” he wrote.

Naidoo was offered his job as Greenpeace’s international executive director in 2009, while on the 19th day of a 21 day hunger strike protesting against Robert Mugabe’s regime and the food crisis in Zimbabwe.

Previously, he had chaired the Global Call to Action against Poverty, a role in which he famously enraged Bob Geldof. Following the G8 meeting at Gleneagles in 2005, Naidoo refused to take part in any of the post-global-poverty-summit-backslapping for which Geldof has become known.

“The world has roared”, Naidoo said, “but the G8 has responded with a whisper.”

Sir Bob defended Tony Blair and other G8 leaders, called Naidoo’s statement a “disgrace”, and gave his own verdict on what had been achieved: “Ten out of ten”, he said.

It will be very interesting to see what Naidoo has planned for the critical UN meeting on global climate change this November – the organizers have obliged him by choosing to hold it in Durban, Naidoo’s hometown.