The United Nations climate talks in Peru entered their final stretch on Friday overshadowed by a long-running dispute over shared responsibility to slow down global warming.

Negotiators in the Peruvian capital, Lima, were expected to attempt to break a deadlock between wealthy and developing countries on the key elements of an international pact to collectively tackle climate change.

Campaigners in Lima, however, said they feared a weak-willed compromise.

"The latest text which countries are working on has been stripped down to its bare bones to accommodate the whims of the lowest common denominator," said Christian Aid's Mohamed Adow. "Right now we are facing the prospect of being no further forward than we were when we left last year's meeting in Warsaw."

The World Wide Fund for Nature (WWF) also voiced concern, saying the new draft "contains a mixed bag of options." The environmental organization said that it was "crunch time for negotiators here in Lima and everything is still up in the air."

On the final day of the talks, WWF posted on the social media website Twitter:

Division on climate draft details

One hundred and ninety-five countries are represented at the climate talks, but many are at loggerheads over how "differentiation" should be applied in the process of declaring national pledges for curbing greenhouse gas emissions.

Developing nations have demanded that the West take on a bigger share of the burden for the carbon cuts, reasoning that they started to pollute the environment decades ago.

However, wealthy nations were quick to point out that fast developing economies like China and India are guilty of burning fossil fuels to power their rapid growth.

Poorer countries also said they want the pledges to incorporate not only action in the push to meet targets, but also financial help and aid to improve their climate defenses.

Individual commitment, collective responsibility

On the penultimate day of the UN Climate Conference, US Secretary of State John Kerry appealed to developing nations to recognize that they too needed to reduce pollution from fossil fuels, even if they felt it was unfair.

"We have to remember that today more than half of global emissions, more than half, are coming from developing nations. So it is imperative that they act, too," Kerry said.

A format for the key sticking point of the pledges must be agreed in Lima to allow countries to start their submissions from the first quarter of next year.

The pledges are to be central to a global climate pact participating nations have agreed to sign in Paris in December 2015.

They are expected to come into effect by 2020 in a bid to limit average global warming to two degrees Celsius (3.6 degrees Fahrenheit) over pre-Industrial Revolution levels.

UN Secretary-General Ban Ki-moon urged ministers and officials on Thursday to embark on "real, serious negotiations."

"We have been talking over the last two decades," said Ban. "We don't have a moment to lose."

The 12 days of talks are expected to end on Friday, but the ongoing dispute over the level of commitment from individual nations threatens to thwart the ambitious environmental accord.

lw/pfd (dpa, Reuters)