People look at large globe in downtown Copenhagen[Agencies]

COPENHAGEN -- The UN's top climate change official on Monday praised developing nations for their contributions to global efforts to rein in greenhouse gas emissions, saying commitments by developing nations could greatly encourage developed nations to make more ambitious pledges.

"What we see happening is that all of those major developing nations are coming forward with exactly those commitments," Yvo de Boer, executive secretary of the United Nations Framework Convention on Climate Change (UNFCCC), told a press conference after the inauguration of the UN Climate Change Conference here.

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De Boer spoke of the efforts by China, which announced last month that it is going to reduce the intensity of carbon dioxide emissions per unit of GDP in 2020 by 40 to 45 percent against 2005 levels. "If you look at the announcement that was made by China alone, that accounts for about 25 percent of the emission reductions that we need to see in order to avoid more than 2 degree temperature increase," he said.

Commitments by developing nations put "a huge amount of encouragement on industrialized nations to increase their level of ambition," he said.

Under the Kyoto Protocol, adopted in 1997, developed countries have committed to reducing their emissions by an average of 5 percent against 1990 levels over the five-year period 2008-2012. Pressure was mounting for developed countries to commit to ambitious targets on cutting emissions and funding for developing nations after 2012.