Meanwhile, the US, one of the biggest greenhouse gas emitters has stalled its climate change legislation in the Senate, resulting in uncertainties in the minds of other states as to what extent they can expect the US to cooperate on any new pledges.

At the same time, some rich countries have requested that the accuracy of emission reporting by the developing countries be checked, but the latter have said such checks are a threat of sovereignty.

Some had forecast that individual agreements reached in Cancun could include issues such as forest protection, financial aid to help developing nations adapt and mitigate the effects of climate change as well as the delivery of low-carbon technologies to such countries.

Despite those divergences and challenges, the process of cooking is expected to begin soon enough.

And, the first kitchen is located in China's coastal city of Tianjin, where a final round of negotiations is scheduled for early October.

This is a chance, as the UN climate chief says, for the countries to make clear what their collective stances are going to be before the negotiation delegations head for Cancun, Mexico at the end of this year.

It seems she doesn't know how long the cooking will take although she needs a miracle before the Cancun conference is held.

China said it is taking actions to help shoulder its global responsibility in fighting climate change. The Chinese delegation head Su Wei said that China's hosting of the talks in Tianjin has indicated the country's strong political determination to push the challenging discussions forward.

But Su played down the expectations for the Cancun conference, urging every party to try hard to achieve progress as much as possible and lay a solid foundation for the South African climate change talks scheduled for next year in Cape Town.

Perhaps, the final three letters of the UNFCCC indicates how long it would take to cook a climate deal: from Copenhagen, to Cancun to Cape Town.

The author is China Daily's chief correspondent in Brussels.