Protests in many countries to demand urgent action on climate change have kicked off, with over 2,000 marches taking place around the world.
The People’s Climate March has been organised to call for action to curb carbon emissions ahead of the UN climate summit in New York next week.
Tens of thousands of people took to the streets in Australia while protests are also getting under way in Europe.
The climax will be a march in New York, attended by UN chief Ban Ki-moon.
He will join thousands of people on the streets of Manhattan, including business leaders, environmentalists and celebrities.
Hollywood actor Leonardo DiCaprio will also attend, having been appointed as a UN representative on climate change last week.
In Australia, organisers said up to 20,000 people had turned out in Melbourne to call on Prime Minister Tony Abbott to do more to tackle climate change.
The BBC’s Phil Mercer in Sydney says protesters fear Australia faces more severe droughts, bushfires and storms unless greenhouse gas emissions are reduced.
‘AN EVERYBODY ISSUE’
Later on Sunday, about 100,000 people are expected to take to the streets in New York.
Organisers of the rally in Manhattan said the massive mobilisation is aimed at transforming climate change “from an environmental concern to an ‘everybody issue.’
On Tuesday, the UN will host a climate summit at its headquarters in New York with 125 heads of state and government – the first such gathering since the unsuccessful climate conference in Copenhagen in 2009.
Ban, the UN’s Secretary General, hopes leaders can make progress on a universal agreement to be signed by all nations at the end of 2015.
He said he would “link arms with those marching for climate action” to show that the UN stands “with them on the right side of this key issue for our common future.”
The New York rally is part of a global protest that includes events in 161 countries – Afghanistan, the UK and Italy among them.