The idea seems simple, but achieving it is a diplomatic nightmare.
Members of the United Nations Framework Convention on Climate Change (UNFCCC) have been wrangling since 1992 over how to tackle global warming.
So far, their big achievement has been the 1997 Kyoto Protocol, which today has the de-facto status of a dodo. A less visible outcome is a tangled knot of mind-numbing issues - from carbon reductions to climate finance to counting forests to offset national carbon emissions - and a requirement for consensus which means just one country can scupper a planetary deal if it feels like it.
In a rare disclosure of frustration, French Ecology Minister Segolene Royal this week said the UNFCCC process was a circus.
"The UN negotiations are totally unsuited to the climate emergency," Royal told Le Monde. "Everyone says so in private, everyone is completely aware of it, but the dead weight of the process is such that it just carries on as usual."
Without political impetus, negotiators will continue "with the same fun and games as they have been having for the last 15, 20 years", Royal said.
"You find hundreds of people with their computer, discussing a bit of disputed text, or filling in crosswords! It's time to change the way things are done."
Royal's sharp language ruffled Foreign Minister Laurent Fabius, whose task it will be to bring the conference - an event expected to draw 25,000 officials, business representatives and activists - to a glittering climax.
But, in interviews with the Paris press, Fabius, too, has shown concern and carefully sought to downplay expectations.
Coaxing consensus from nearly 200 countries "will be extremely difficult", Fabius said, stressing "if there is a Paris agreement" it would not resolve the climate problem but "be the start" of the process to fix it.
The negotiations, he observed, were haunted by the "Copenhagen Syndrome" - the lingering trauma of what happened in the Danish capital in 2009. That was when the UNFCCC last set a goal of a climate accord - a treaty to take effect from 2012.
Around 115 heads of state and government flew in for the conference's final day, blithely expecting to give the agreement their blessing.
Instead, they stumbled into a minefield. The situation was deadlocked and the mood angry and tribalistic. Exhausted negotiators wrangled over sub-clauses yet made not an inch of progress.
As the summit ran into overtime, leaders from the world's three dozen biggest economies huddled in the back rooms to try to avoid a fiasco. They hammered out a face-saving deal under which warming would be limited to 2C and climate-vulnerable countries would get US$100 billion ($140 billion) per year in aid by 2020.
Developing nations howled at being sidelined while incensed activists said the deal lacked basic stuff - things such as setting a trajectory towards 2C, a compliance mechanism to stop countries from cheating, details on how the promised aid would be mustered and even the accord's status in law.
Today, the secretive deal struck in Copenhagen has been accepted by all as the heart of the post-2020 pact. It also incorporates a roster where all countries, for the first time, are to inscribe national pledges of carbon cuts.
But even now, the basic stuff that was notoriously missing in Copenhagen remains to be agreed.
And, so far, only a few dozen countries have submitted their pledges, amounting to only a third of global emissions.
Speaking in Bonn at the start of a new round of talks, Fabius last Monday announced he would host ministerial meetings in July and September, in addition to two other scheduled UNFCCC gatherings in September and October, thus heaping on pressure to ensure things are not left to a last-minute haggle.
Climate will also feature at the G7 summit in Germany tomorrow and on Monday and among heads of government at the UN General Assembly in New York in September.
"The goal is for us to reach a pre-agreement as early as October," said Fabius.
But a protocol problem is starting to brew. President Francois Hollande - desperate for a star turn on the world stage - is keen on turning the Paris conference into a summit but the environment ministry is terrified of a rerun of Copenhagen.
A compromise idea is to invite leaders at the conference's start, to boost negotiations, rather than at the end, when they could be humiliated if the talks flop.
But Fabius is treading cautiously, and may wait to assess progress in October before sending out any invitations.
World warming up to be hottest year yet
The world is on course to have its hottest year on record, according to climate change experts, who fear global warming is set to send temperatures soaring.
There have already been a number of temperatures records set this year with Antarctica experiencing its two warmest days ever recorded in March.
Equatorial Guinea, Ghana, Venezuela and Laos have all set national temperature records in the past five months, while globally January to April this year has been the warmest on record at 0.68C above average.
The past 12 months have already been the warmest on record.
According to the Times, Professor Adam Scaife, who leads the monthly to decadal climate prediction research at Britain's Met Office, said: "There's a pretty good chance of the global record being broken this year."
Earlier this year, it was revealed that 2014 was the hottest on record - but now 2015 looks set to surpass that.
- NZ Herald, Daily Mail
