Hundreds of thousands of activists marched around the world on 29 November to urge action on a global scale on the eve of a UN climate summit in Paris. At least 50,000 people marched through London in what was the UK's largest ever demonstration for action against climate change . Demonstrators gathered on Park Lane and marched through London, past Trafalgar Square, Downing Street and Parliament before finishing at Millbank, where speakers from a number of organisations addressed the crowd.

In Amsterdam, around 7,000 people marched in a bid to pressure politicians to find solutions and reduce the effects of climate change. Faiza Oulahsen, a spokeswoman for the non-governmental organisation Climate Coalition, described how the worldwide protests had to get across the message that time was running out.

"Thousands of people have gathered here today to protest against climate change," she said. "This is part of a global day of action. In over 150 countries, hundreds of thousands have taken to the street to raise their voices against climate change. Tomorrow, over 150 world leaders gather [in Paris] to discuss climate change and try to reach a climate agreement. Time is running out. 2015 has been a year with the hottest temperatures ever measured. Around the world, the consequences of climate change are felt. It is time for action."

In Rome, crowds gathered at Campo Dei Fiori, close to the French embassy, as a show of solidarity to France after the 13 November attacks before marching through the historical centre towards Piazza Venezia. Many held placards that said: "There is no Planet B." The demonstrations were part of the more than 2,000 climate events planned in cities across the world, making it one of the biggest days of action on climate change in history, organisers said. Most were hopeful that something concrete would be achieved at the summit.

"If we confront and start to resolve the climate problems, we will also start to resolve the underlying reasons of the huge conflicts across the world," said Vittorio Cogliati Dezza, the president of one of Italy's largest environmental organisations, Legambiente. "We hope that there will be foresight... there is the possibility because today the governments' and the institutions' knowledge has increased."

Activists in France scaled back their plans when the government imposed a state of emergency after the attacks two weeks ago killed 130 people, banning the planned demonstration in Paris, meant as the biggest of all. Separately, more than 10,000 demonstrators who had planned to go to Paris instead sent shoes to form a big pile as a sign of solidarity. Organisers said the Vatican even sent a pair to represent Pope Francis.