Act Now On Climate, Summit Urged
Danish Prime Minister has described the UN climate summit in Copenhagen as an "opportunity the world cannot afford to miss".
Opening the two-week conference in the Danish capital, he told delegates from 192 countries a "strong and ambitious climate change agreement" was needed.
About 100 leaders are to attend the meeting, which aims to strike a deal on major cuts in greenhouse gas emissions.
The UN says an unprecedented number of countries have promised emissions cuts.
But on the first day of the summit, divisions were evident between various blocs, with small island states indicating they would not accept anything less than a legally binding deal including deep cuts in emissions.
In July, the G8 bloc of industrialised countries and some major developing countries adopted a target of keeping the global average temperature rise since pre-industrial times to 2C.
However, small island states think this would cause serious climate impacts from rising sea levels, and have been arguing for a lower target of 1.5C. A number of African nations also back the lower target.
BBC environment correspondent Richard Black say it is possible that the G77/China bloc will endorse the lower target.
He says this would raise a huge obstacle, because none of the industrialised countries have put forward emission cuts in the range that would be required to meet a 1.5C target.
The African Union has threatened to walk out of the talks if industrialised countries do not agree to help poor states pay for the transition to cleaner economies.
The main areas for discussion at Copenhagen include:
Targets to curb greenhouse gas emissions, in particular by developed countries.
Financial support for mitigation of and adaptation to climate change by developing countries. A carbon trading scheme aimed at ending the destruction of the world's forests by 2030.
Any agreement made at Copenhagen is intended to supplant the 1997 Kyoto Protocol on climate change, which expires in 2012.
World leaders who have pledged to attend include US President Barack Obama, UK Prime Minister Gordon Brown, French President Nicolas Sarkozy and Indian Prime Minister Manmohan Singh.
Source: BBC