PARIS (AFP) - Masses of people joined a worldwide wave of marches on Saturday demanding leaders craft a pact to avert a climate catastrophe when they gather in a still-shaken Paris.
From Australia to New Zealand, the Philippines, Bangladesh and Japan, people rallied at the start of a weekend of popular protests pleading for world powers to overcome the logjams when the UN climate summit officially opens in the French capital Monday.
"Protect our common home," declared placards held aloft as thousands gathered in Melbourne, with those sentiments echoed also on the streets of Johannesburg and Edinburgh.
Some 150 leaders, including US President Barack Obama, China's Xi Jinping, India's Narendra Modi and Russian President Vladimir Putin, will attend the start of the Paris conference, which is tasked with reaching the first truly universal climate pact.
The goal is to limit average global warming to 2 deg C, perhaps less, over pre-Industrial Revolution levels by curbing fossil fuel emissions blamed for climate change.
If they fail, scientists warn of a world that will be increasingly inhospitable to human life, with superstorms, drought and rising sea levels that swamp vast areas of land.
On the eve of Saturday's protests, French President Francois Hollande warned of the obstacles ahead for the 195 nations following more than two decades of bickering.
"Man is the worst enemy of man. We can see it with terrorism," said Hollande, who spoke after leading ceremonies in Paris to mourn the victims of the deadly Nov 13 bombing and shooting attacks that sowed terror in the French capital.
"But we can say the same when it comes to climate. Human beings are destroying nature, damaging the environment. It is therefore for human beings to face up to their responsibilities for the good of future generations."
Potential stumbling blocks in Paris abound, ranging from financing for climate-vulnerable countries to scrutiny of commitments to curb greenhouse gases and even the legal status of the accord.
The last attempt to forge a global deal - the ill-tempered 2009 Copenhagen summit - foundered upon divisions between rich and poor countries.
UN Secretary-General Ban Ki-Moon said he was optimistic of success in the talks, which are due to end on Dec 11, but emphasised all sides must be prepared to compromise.
"I am urging the world leaders that they must agree on the middle ground, there is no such perfect agreement in this world," Ban told France 24 television on Saturday.
Briefing reporters at the summit venue, French Foreign Minister Laurent Fabius highlighted four key issues still dividing nations but also voiced optimistim about Paris success.
He pointed out the number of nations that had submitted plans on how they intended to fight climate change - a key part of the planned Paris agreement - had risen to 183 and covered 95 per cent of greenhouse gas emissions.
"This is extremely good news," he told reporters.
Speaking alongside Fabius, UN climate chief Christiana Figueres said the voluntary carbon-curbing pledges would still put Earth on track for warming of between 2.7 and 3.5 deg C.
Figueres said, while this was not nearly enough, the pledges had moved the world away from warming of up to six degrees.
"That is fundamental progress," she said, adding the Paris agreement could "chart the path" for continued improvement in the years ahead to keep warming to between 1.5 and 2 deg C.
In other positive developments, billions of dollars in environmental aid were revealed Friday.
In Ottawa, the Canadian government announced climate funding of 2.65 billion Canadian dollars over the next five years, while the 53-nation Commonwealth bloc agreed to set up a billion-dollar "Green Finance Facility" for environmental projects.
Protest organisers say they expect hundreds of thousands to take to the streets globally this weekend ,with further rallies planned for Sunday in Seoul, Rio de Janeiro, New York, Kiev and Mexico City.
In Paris, French authorities cancelled two demonstrations following the onslaught by gunmen and suicide bombers which killed 130 people at restaurant terraces, a concert hall and the national stadium on Nov 13.
People rallying this weekend have declared their solidarity with activists unable to rally in Paris with a social media campaign tagged #march4me.
Activists still plan to create a 2km human chain along the original march route on Sunday.
They will break the chain as they pass the Bataclan concert hall, where the worst violence claimed 90 lives, as a mark of respect to the victims.
Protesters also plan to leave scores of shoes on Place de la Republique square to symbolise the thousands left frustrated in their plans to march.
In a sign of the urgency of the talks ahead, the start of the climate negotiations themselves, conducted by rank-and-file bureaucrats, have been brought forward to Sunday on the eve of the official opening.
The Paris conference will gather some 40,000 people, including 10,000 delegates from 195 countries.
About 2,800 police and soldiers will secure the conference site, and 6,300 others will deploy in Paris.