Tens of thousands demonstrated in Australia, to be followed by events in Seoul, Rio de Janeiro, New York and Mexico City on Sunday on a third day of worldwide rallies.
Marches took place in New Zealand, the Philippines, Bangladesh, Japan, South Africa and the UK on Saturday.
The message to curb global warming and help poor countries deal with climate change was echoed by religious leaders in Paris, who delivered petitions with almost 1.8 million signatures from people around the world.
A planned march in Paris on Sunday was cancelled and rallies banned in the aftermath of the Paris attacks but some 3,000 people planned to form a human chain, broken at the Bataclan concert hall which was the scene of the worst massacre, and shoes sent by 10,000 people who would have marched were laid out in the Place de la République.
Analysts say voluntary carbon-curbing pledges submitted by nations to bolster the Paris pact, even if fully adhered to, will only limit warming to 3.0°C, below the official target of 2.0°C higher than pre-industrial revolution levels.
In a sign of the urgency they feel is needed, Cop21's organisers have brought forward the start of negotiations to Sunday evening.