Six women have climbed the outside of Western Europe's tallest building.
The six women climbed on to the roof of London Bridge Station via the temporary ticket office building before making their way up the tower.
The climbers intend to unveil an artwork when they reach the summit.
The Metropolitan Police says that they were alerted to the protest at 4.20am on Thursday.
The London Ambulance Service also sent emergency response vehicles to the scene.
Part of the concourse of London Bridge Station below the Shard was sealed off in case the climbers fell.
Greenpeace says the stunt is designed to raise awareness of Shell's Arctic drilling plans.
On the Shard's official Twitter account the building's owners said: "Our key focus is on safety of all at our building and we're working with relevant authorities."
The drama meant that bus routes 48 and 149 were unable to use London Bridge Bus Station.