Leaders from the world emerging economies agreed on Thursday to limit the global warming to within 2 degrees Celsius above pre-industrial levels, but they failed to hammer out more substantial targets of cutting greenhouse gas emissions.

"We recognize the scientific view that the increase in global average temperature above pre-industrial levels ought not to exceed 2 degrees Celsius," the leaders said in a declaration after a meeting under the format of Major Economies Forum (MEF), which brought together 17 nations including the Group of Eight (G8) industrialized countries and five emerging economies including India, China, Brazil, Mexico and South Africa.

Describing it as an "historic consensus," U.S. President Barack Obama, who chaired the forum meeting, said rich countries have a responsibility to take the lead on climate change.

"We agreed that the developed nations have a responsibility to take a lead," he said. "The United States has a historic responsibility to take the lead. In the past, the United States has sometimes fallen short in meeting its responsibilities."

Scientists warned that there would be serious climate consequences if the world temperature rises more than the threshold of two degrees Celsius, but Washington had been reluctant to accept the threshold of 2 degrees Celsius under the previous administration of President George W. Bush.

Behind the achievement, the world emerging economies actually failed to bridge their major differences on the concrete targets of reducing greenhouse gas emissions, leaving huge jobs to be done when world governments meet in Copenhagen, Denmark by the year end to work out a new global pact on climate change to replace the current Kyoto Protocol which expires in 2012.

"Developed countries among us will take the lead by promptly undertaking robust aggregate and individual reductions in the midterm consistent with our respective ambitious long-term objectives and will work together before Copenhagen to achieve a strong result in this regard," the declaration said, containing no target figure.

The G8 leaders agreed on Wednesday to achieve the goal of reducing global emissions by at least 50 percent by 2050, pressing others to share the burden, but they failed to specify from the level of which year the emissions should be halved.

The EU has been pushing for reduction by half from the base year of 1990, while the U.S. wants to use the emission level in 2005, which is higher than that in 1990, as the reference.

As part of the long-term effort, the G8 leaders also supported a goal of developed countries reducing emissions of greenhouse gases in aggregate by 80 percent or more by 2050 compared to 1990 or more recent years.

However, emerging economies would like to see rich nations make deeper cuts in the medium term, namely by 2020, rather than a distant target by 2050, which is less relevant.

They are seeking a commitment by developed countries, which are historically responsible for the global warming and should bear larger share of burden, to make a cut of at least 40 percent by 2020 compared to the level of 1990.

Developing countries also want developed nations to provide financing and technology transfer to help the poor in the fight against climate change before they can accept any big cuts.

Obama said that developed countries agreed to increase resources and provide financial assistance to help developing countries in dealing with climate change, but the financing issue was left to a summit of the Group of 20 (G20) major economies in the U.S. city of Pittsburgh in September.

Speaking at a press conference, Italian Prime Minister Silvio Berlusconi, the host, said emerging economies will undertake to abide by certain commitments.

"Developing countries among us will promptly undertake actions whose projected effects on emissions represent a meaningful deviation from business as usual in the midterm, in the context of sustainable development, supported by financing, technology, and capacity-building," leaders from the world major economies said in the declaration.

UN Secretary General Ban Ki-moon immediately reacted to the result by criticizing it as insufficient.

"The commitments expressed today at the G8 and MEF leaders' meeting, while welcome, are not sufficient," Ban said in a statement. "Much more needs to be done if governments are to seal the deal on a new climate agreement in December in Copenhagen."

Ban urged developed countries to take the lead by making firm commitments to reduce their emissions by 2020 in line with the 25 to 40 percent below 1990 level.

"For this to be credible, however, we need ambitious midterm targets and clear baselines," Ban said. "It is disappointing to note that thus far, the midterm emission targets announced by developed countries in the MEF are not in this range."

Humanitarian charity ActionAid blamed developed countries for the poor progress, warning it left mountain to climb to reach just global deal in Copenhagen.

"Rich countries have failed to breathe new life into the international climate change negotiations at the G8 and Major Economies Forum, refusing to state by how much they will reduce carbon emissions by 2020," ActionAid said in a statement.

"The global target the G8 agreed to, a 50 percent cut in global emissions by 2050, is too far away. The G8 need to reduce their emissions by 40 percent by 2020 against 1990 levels," it said.

(Xinhua News Agency July 10, 2009)