Climate protests may not change policy in the immediate future, but they represent a big environmental awakening

Analysis: Extinction Rebellion activists have science on their side

Climate change is the biggest single issue facing our planet, and as frustration over the lack of action in tackling its causes reaches boiling point, thousands have taken to city streets around the world.

Swathes of central London have been brought to a halt for a third day as protesters demanding government action have occupied major landmarks and defied police orders to move on.

Almost 300 people have been arrested, 55 bus routes through the capital have been diverted, parts of the Tube system have been disrupted, and an estimated half a million commuters have been affected.