The action is being led by the radical Extinction Rebellion group with the aim of moving governments worldwide to "take decisive action on the climate and ecological emergency."
On Monday, police imposed a 24-hour "condition" on Waterloo Bridge and Oxford Circus, two of London's busiest locations, to prevent protesters from gathering, but videos published on the Extinction Rebellion Twitter page show protests are still going strong.
The videos show activists singing and dancing, as well as some being dragged away and arrested by police.
Meanwhile, one activist glued himself to a train window in Canary Wharf, one of London's busiest financial centers, and two activists glued themselves to the top of the train unfurling a banner that read "Climate Emergency."
Two men and one woman were arrested "on suspicion of obstructing the railway" after specialist teams "trained in protest removal" arrived on the scene, British Transport Police said in a statement.
And the protests could continue for the foreseeable future, according to Extinction Rebellion activist Roger Hallam, who said they were protesting to "inform the British people that they will die if we do not stop the government from putting greenhouse gases into the atmosphere."
"We are in ongoing rebellion against the government," he told ABC News. "It will end when we get the demands met. This particular mobilization will continue for one to two weeks depending on whether many people join in mass civil disobedience."
Sadiq Khan, the Mayor of London, said Tuesday while he shared the protesters' "passion" for the need to tackle climate change, he was "extremely concerned" by the disruption to London's public transport.
"It's one of the biggest challenges we face -- and Governments around the world are failing to take the action we need," he said in a statement. "However … targeting public transport in this way would only damage the cause of all of us who want to tackle climate change, as well as risking Londoners' safety, and I'd implore anyone considering doing so to think again."