World leaders are in Paris for two weeks urging one another to find common cause in an ambitious attempt to hold back the earth's rising temperatures.
Correspondent Ivor Bennett looks at how investors are viewing the pivotal climate conference and what sort of deal might be reached.
In case the world needed a reminder of the challenge it faced, this was it.
Beijing - the capital of the world's biggest carbon emitter - blanketed in smog.
The backdrop to climate talks in Paris whose significance seems impossible to overstate.
French foreign affairs minister and conference president, Laurent Fabius.
(SOUNDBITE) (French) FRENCH FOREIGN AFFAIRS MINISTER, LAURENT FABIUS, SAYING:
"The world is looking at us, and there is a lot of hope. It's our role to put up and accept our responsibility."
Over 150 world leaders are taking part in the conference.
The pressure to agree a deal on how to reduce global carbon emissions perhaps greater than ever.
Activists gathering around the world on the eve of the summit to remind them there is 'no planet B'.
But CMC Markets' Jasper Lawler is skeptical it'll have any effect.
SOUNDBITE (English) JASPER LAWLER, MARKET ANALYST, CMC MARKETS, SAYING:
"I think what we're probably going to at this stage, at least, in Paris, is some sort of, if you like, quote unquote weak deal, whereby no specific quotas are mentioned or probably the financing is not exactly put into really finite detail."
Who'll pay for a shift to renewables is a big part of the problem.
India's power minister reigniting the tensions that scuppered previous talks with a call for developed nations to shoulder more of the burden.
For companies though, there is money to be made, says Paul Dickinson from sustainability consultants CDP.
SOUNDBITE (English) PAUL DICKINSON, EXECUTIVE CHAIRMAN, CDP, SAYING:
"Climate change is like the internet. It gets bigger every year, it never goes away and you have to learnt to make money from it and there are big opportunities for technology companies delivering in this realm."
In front of the cameras, at least, there was no sign of any tensions.
But if leaders are to reach a consensus within two weeks, relations are likely to be strained.