Representatives from 200 countries are gathering in Cancun for this year's UN climate summit. But hopes aren't high that there will be any global deal as a result.
Hopes were high that a formal international treaty would be thrashed out at last year's Copenhagen summit. In the event, though, a compromise deal was struck without the participation of many members and which green campaigners saw as a feeble compromise.
While more than 180 nations approved the deal, the handful of hold-outs meant it never gained official status.
"An international climate change agreement could catalyse and help pay for a world with clean, secure and independent means of energy guaranteed for generations to come," says Greenpeace.
"It could keep natural and ancient forests standing and forest peoples thriving, as well as protecting many forest species and helping to stop catastrophic climate change."
The aim is to build on the Kyoto Protocol, which sets limits for greenhouse emissions for all industrialized nations - except the US, which refused to sign, objecting that the deal should have included binding targets for developing nations.
The EU is calling for the US to come into the fold, along with other major polluters such as China and India. China baulked last time round at the US' insistence that all promises on emission reductions should be verifiable.
More likely is agreement on various smaller issues, such as the creation of a green fund to help share technologies and protect tropical forests, which act as carbon soaks.
One of the aims of the conference is to establish how the necessary $100 billion per year will be raised, and this at least has a reasonable likelihood of being achieved - although there are doubts once again whether the US will deliver.
Next year's conference is scheduled to take place in South Africa. But if there's no real progress made in Cancun first, those voices grumbling that the UN Framework Convention on Climate Change has had its day may start to gain greater authority.