It was unlikely that the upcoming 16th conference of parties, or COP16, to be held in Cancun, Mexico later this month, will deliver a global agreement, Department of Environmental Affairs deputy director-general, and South Africa's lead negotiator at the conference, Alf Wills said on Tuesday.

Since the 15th COP, held in Denmark last year, there has been a distinct loss in the momentum of these climate change negotiations, while the deep division between developed and developing nations has persisted, he told a South African Institute of International Affairs gathering.

The US has been unable to pass climate legislation, making it unwilling to sign any legally binding emission reduction targets, resulting in other developed nations not being prepared to agree to internationally legally binding commitments beyond the Kyoto protocol, which lapses in 2012.

One of the fastest growing emerging nations China is also not likely to enter into a legally binding agreement unless the US does.

The current stalemate would likely result in a possible gap between the end of the Kyoto Protocol and the start of a second commitment period, said Wills.

He further pointed out that an inability to reach a global consensus in future would hit Africa the hardest.

At COP15 it was agreed that global warming should be kept below 2 ˚C.

However, a 4˚C to 5˚C increase in temperatures was much more likely, which could reverse all the development gains made in Africa in the past few years, as well as lead to issues of food security, he noted.

Wills said that South Africa was hoping that a decision on the overarching legal shape and form of a second commitment period and a mandate to continue negotiations has to be reached at Cancun.

Meanwhile, Mexican ambassador to South Africa Luis Cabrera commented that greater flexibility by all parties involved in the COP16 negotiations was needed at this crucial stage of negotiations.