UN secretary-general Ban Ki-Moon: An essential beginning

UN climate chief Yvo de Boer: "The challenge is now to turn what we have agreed politically in Copenhagen into something real, measurable and verifiable.”

After the climate summit in Copenhagen Saturday morning agreed to "take note" of the Copenhagen Accord, UN Secretary-General Ban Ki-moon concluded that "finally, we sealed the deal," BBC reports.

According to AP, he added that he was aware this was just the beginning of a process to craft a binding pact to rein in greenhouse gas emissions, but pointed out that the agreement would have "an immediate operational effect."

"It may not be everything we hoped for, but this decision of the Conference of Parties is an essential beginning ... The importance will only be recognized when it's codified into international law ... We must transform this into a legally binding treaty next year," he said according to BBC.

Head of the UN Framework Convention on Climate Change secretariat, Yvo de Boer, was not that enthusiastic. 

In a press release from UNFCCC he stated: “We must be honest about what we have got. The world walks away from Copenhagen with a deal. But clearly ambitions to reduce emissions must be raised significantly if we are to hold the world to 2 degrees.” 

Because the pledges listed by developed and developing countries may, according to science, be found insufficient to keep the global temperature rise below 2 degrees or less, leaders called for a review of the accord, to be completed by 2015.

The review would include a consideration of the long-term goal to limit the global average temperature rise to 1.5 degrees.

119 world leaders attended the Un summit in Copenhagen, the largest gathering of heads of state and government in the history of the UN. “Climate change is the permanent leadership challenge of our time,” said Ban Ki-moon. “I therefore urge world leaders to remain engaged,” he said.