Thousands march as UN climate talks head to crunch phase

Pope Francis has urged nations to act with "courage" while 10,000 climate activists took to the beach in Belgium, a day before UN talks enter their crunch phase in the search for a historic pact against global warming.

Ministers begin a frenetic week of negotiations today to seal a historic 195-nation agreement in Paris.

The envisaged deal seeks to revolutionise the world's energy industry by replacing coal, oil and gas with renewable sources that do not emit heat-trapping greenhouse gases.

The talks in Le Bourget, just north of the French capital, crown more than two decades of fraught negotiations to curb climate change, which threatens to make Earth increasingly hostile to human existence.

Speaking before thousands of worshippers in the Vatican yesterday, Francis said he prayed that leaders would muster "the courage to keep as their guiding criterion the well-being of the entire human family".

And near Ostend in Belgium, more than 10,000 climate activists pushing for an "ambitious, fair and binding" deal marched along the beaches.

In Paris, a coalition of African nations and donors on Sunday unveiled an ambitious initiative to restore 100 million hectares (25 million acres) of degraded and felled forests, to absorb CO2 and provide a livelihood for the poor.

The talks opened November 30 with a record-breaking gathering of 150 world leaders who issued a chorus of warnings about mankind's fate if global warming goes unchecked.

"The future is one that we have the power to change right here, right now, but only if we rise to this moment," US President Barack Obama told the summit.

Negotiators spent the rest of last week trying to address the many deep and complex divisions among countries with competing national interests -- rows that have condemned previous UN efforts to failure.

While none of the major arguments have been resolved, negotiators did meet Saturday's deadline to produce a draft for the agreement, showing enough compromise to offer hopes for cautious optimism.

Environment and foreign ministers will take the blueprint up today, seeking to eliminate hundreds of bracketed words or sentences that indicate disagreement.

Small island nations most vulnerable to rising sea levels and stronger storms, often railroaded by the powerful in the UN talks, said they were relieved their voices were being heard in Paris.

"We would have wished to be further along than we are at this point, but the text being forwarded so far reflects our key priorities," said Thoriq Ibrahim from the Maldives.

China, after being accused of contributing to the spectacular failure of the last attempt at a global climate pact in Copenhagen six years ago, offered encouraging words.