Tens of thousands of people are marching in global cities today to call for action on climate change ahead of a meeting of world leaders in Paris.

At the People’s March For Climate in London, Thom Yorke joined Greenpeace’s arctic-themed float to DJ as the demonstration made its way through the city, as captured by the environmental activist group on Twitter and Facebook with a snippet of Caribou. (Best bit: someone rings a bell and Yorke leaps into the air with fright.)

Yorke, who this week signed an open letter from the creative community urging international leaders to reach a deal at the conference, recently published a conversation with environmental writer George Monbiot in which he claimed that Tony Blair’s advisers tried to blackmail him into meeting the former prime minister.

Yorke is also planning to perform at Le Trianon next week for the Pathway To Paris climate change concert, as Stereogum reports. Read a brief update from Greenpeace about why these talks might actually lead to action.