The United Nations climate change talks this week in Bonn, Germany, made important progress in fleshing out how a climate regime can work in practice, but the outgoing head of the UN body on this issue warned participants that the long-term goal of cutting emissions will not be reached without stringent action.

"The two-degree-world is in danger," said Yvo de Boer, the Executive Secretary of the UN Framework Convention on Climate Change (UNFCCC), referring to the goal of limiting global warming to a rise of 2 degrees Celsius as compared to temperatures in pre-industrial times.

"A big step forward is now possible at Cancún, in the form of a full package of operational measures that will allow countries to take faster, stronger action across all areas of climate change," Mr. de Boer added, referring to the climate summit in Mexico at the end of the year.

He was speaking at the conclusion of a two-week meeting where more than 5,500 participants, including delegates from 185 governments, attempted to conclude what was left incomplete since the talks in Copenhagen last December.

Two working groups met in parallel. One focused its talks on the long-term response to climate change, such as adaptation to its inevitable effects of climate change, the transfer of clean technology, reducing emissions from deforestation and capacity building, along with finance and institutional arrangements.

The other working group focused on emissions reduction commitments for the 37 industrialized countries that that have ratified the Kyoto Protocol for the period beyond 2010, and on ways to turn the emission reduction pledges into targets.

Mr. de Boer called on participants to take a "cold look" at the 76 emission reduction and emission limitation pledges that have been made by developed and developing countries since the Copenhagen Conference.

"Take all current pledges and plans from all countries and we still won't stop emissions growing in the next 10 years," Mr. de Boer warned, noting that industrial country pledges are below the 25 to 40 per cent reduction rate that the Intergovernmental Panel on Climate Change (IPCC) has said was needed to keep global temperatures in check.

Mr. de Boer, who will step down in a few weeks to pursue new opportunities to advance progress on climate change in the private sector and academia, will be replaced by Christiana Figueres of Costa Rica.

The next UNFCCC negotiating session is scheduled to take place in early August, also in Bonn, followed by a second one-week inter-sessional meeting ahead of the UN Climate Change Conference to be held from 29 November to 10 December in Cancún.