Amid warnings from experts that global warming is likely to exceed an agreed 2C threshold if carbon emissions continue at the current rate, climate talks in Bonn ended Friday with no substantive movement on the issue of binding carbon targets.

Majority of the negotiators from 192 countries that participated in the two-week climate change talks in Bonn feared that an all-encompassing agreement on binding carbon emissions is unlikely to be achieved at the major climate conference in Durban this December to replace the current Kyoto Protocol.

Many governments fear binding emission commitments could affect their economic competitiveness.

The 1997 Kyoto Protocol agreement will expire at the end of 2012 raising the possibility of a regulatory gap if a new deal cannot be reached before then.

UN Framework Convention on Climate Change (UNFCCC) executive secretary Christiana Figueres said that the economic crisis was making it harder to make progress in the talks.

An agreement to reduce carbon emissions "is the most important negotiations the world has ever seen, but governments, business and civil society cannot solve it in one meeting," Figueres said at the close of the conference in Bonn.

The EU has signified their willingness to a second commitment period under the Kyoto Protocol but warned that developing countries who are major polluters must make binding commitments as well.

"We need to get real answers on how we can bridge the gap between pledges (made under the 2009 Copenhagen Accord) and what's needed," said Jurgen Lefevere, European Commission negotiator, referring to what other major emitters like US and China needed to do.

Lefevere said that a renewal alone of the Kyoto Protocol "is not going to cut it. We need to bring other big emitters into a robust regime."

The US never ratified the Kyoto Protocol, while China, the biggest emitter was given no emission cap with its status as a developing economy.

Jonathan Pershing, chief US negotiator, said the US is "not prepared to have a legal agreement that would apply to us and not to others". Pershing ruled out making any further commitments beyond its target to cut emissions by 17% by 2020.

Japan, Russia and Canada refused to participate to a second Kyoto commitment period.