The UN has received pledges from 55 countries, accounting for 78 per cent of global emissions, to cut their share of greenhouse gases by 2050, a development welcomed by the world body as an 'important invigoration' to the Copenhagen climate talks.
Some of the world's biggest polluters, the US, China, European Union and India, have reiterated their previous pledges of cutting emissions by 2020 that were widely regarded as weak, especially the 17 per cent reduction of carbon emissions from 2020 levels proposed by the US.
Experts have noted that the current pledges are not sufficient to meet the goal set to limit global temperature rise to two degree Celsius.
But the UN welcomed these countries joining the Copenhagen Accord, the agreement that was produced following the climate talks in the Danish capital in December.
"The commitment to confront climate change at the highest level is beyond doubt," said UN's Climate Chief Yvo de Boer, noting that the pledges represented an 'important invigoration' of the discussions at Copenhagen.
"Greater ambition is required to meet the scale of the challenge. But I see these pledges as clear signals of willingness to move negotiations towards a successful conclusion," he added.
The accord set a deadline for the end of January for countries to set and submit their mitigation targets.
China has pledged to reduce its carbon intensity by 40 to 45 per cent by 2020, compared with 2005 levels while India has pledged to cut its carbon intensity by 20 to 25 per cent. Mexico has yet to submit its target.
The accord was produced by 29 countries, but principally drafted by the US, China, India, Brazil and South Africa, in the last few hours of the conference, and was slammed by certain countries, including Bolivia, Venezuela, Nicaragua and Cuba for having left the majority of the nations out of the negotiating process.
Key elements of the accord included limiting to 2 degrees Celsius the rise in global temperatures, a $100-billion finance in long term finance to developing countries and $30 billion to short-term finance to the poorest and most vulnerable countries.
There is still no clear mechanism for the actual collection and disbursement of this aid but the next round of formal negotiations is scheduled for May in Bonn.
The next big COP will be held at the end of the year in Mexico.
The talks in Copenhagen were expected to produce a legally binding treaty on combating the climate crisis.