U.N. Secretary General Ban Ki-moon called Friday on envoys from around the world to take a "final decision for humanity" as they battled to seal a 195-nation climate-saving pact in Paris.

"This negotiation is most complicated, most difficult, but most important for humanity. We have just very limited hours remaining," Ban told reporters as ministers grappled with stubborn differences over pivotal issues.

Sleep-starved envoys tasked with staving off catastrophic climate change are on track to seal a historic accord, the French hosts of UN talks said Friday although the biggest pitfalls were yet to be cleared.

The 195-nation conference in Paris had been scheduled to wrap up on Friday, but was extended another day after ministers failed to bridge deep divides during a second consecutive all-night round of negotiations.

Australia should introduce a “post-disaster humanitarian visa” for Pacific islanders displaced by natural disasters and climate change, a new report from the Migration Council Australia has recommended.

And to boost historically low rates of migration from the Pacific, Australia should consider instituting a green card-style lottery for Pacific islanders to live and work in Australia, and boost seasonal worker numbers to industries such as horticulture.

UN climate talks in Paris tasked with beating back the threat of global warming are scheduled to conclude on Friday.  

This is what brought them together in the first place:

Beijing's first ever red alert for smog expired Thursday, as blue skies and sunshine replaced the thick haze that covered the city for days.

The Chinese capital put its air pollution emergency plan into action earlier this week, pulling half of all private vehicles off the streets from Tuesday, ordering many factories to close and recommending that some schools allow students to remain home.

Karachi, 2050: The sprawling megacity lies crumbling, desiccated by another deadly heatwave, its millions of inhabitants suffering life-threatening water shortages and unable to buy bread that has become too expensive to eat.

It sounds like the stuff of dystopian fiction but it could be the reality Pakistan is facing. With its northern glaciers melting and its population surging -- the country's climate change time bomb is already ticking.

Tears flow often -- blood has once -- as climate negotiators from 195 nations gather every year in a different corner of the world for a physical and emotional endurance race.

Nerves are known to fray as the delegates' high-stakes mission to save humanity clashes head-on with the intransigence that comes from their other mandate to defend narrow national interests.

Ministers in Paris have until Friday to conclude a 195-nation pact to stop Earth's climate becoming inhospitable to humans and other species.

If humankind continues to emit greenhouse gases unabated, the average global temperature by 2100 will be about 5.2 degrees Celsius (9.4 degrees Fahrenheit) higher than pre-Industrial Revolution levels.

French hosts of 195-nation climate rescue talks released a crucial new blueprint Wednesday, reporting important progress but some sticking points two days ahead of the deadline for a U.N. deal.

Foreign Minister Laurent Fabius said the document revealed "emerging compromises" on the way to a historic agreement to rein in heat-trapping greenhouse gas emissions that warm the planet.

Wealthy nations have come under attack from developing countries over proposed financial commitments designed to help them deal with the effects of global warming.

The row, which came at the close of the first week of the crunch Paris climate talks, was over the wording of a proposal in the draft text of a potential agreement released on Friday, which became the subject of long negotiations into the early hours of Saturday morning.