U.N. says nations' greenhouse gas pledges too little

Janos Pasztor, Secretary-General Ban Ki-moon's top climate adviser, said the goals, submitted to the U.N. as part of a voluntary plan to roll back emissions, make it highly unlikely the world can prevent temperatures from rising above the target set at the Copenhagen climate conference in December.

Fifty-five nations — including China, the United States and 27-member European Union — met a Jan. 31 deadline to submit pledges to the U.N. for cutting those emissions. Together they produce 78 percent of the world's greenhouse gases stemming from fossil fuel burning. The deadline had been set at the Copenhagen conference.

More such commitment letters were expected to continue trickling in over the next several days.

"It is likely, according to a number of analysts, that if we add up all those figures that were being discussed around Copenhagen, if they're all implemented, it will still be quite difficult to reach the two degrees," Pasztor told the Associated Press.

The "two degrees" refers to the Copenhagen target of keeping the Earth's average temperature from rising two degrees Celsius (3.6 degrees Fahrenheit) above the levels that existed before nations began industrializing in the late 18th century. It would be no more than 1.3 degrees C (2.3 degrees F) above today's average temperatures.

"That is the bottom line, but you can look at it negatively and positively," Pasztor said. "The negative part is that it's not good enough. The positive side is that for the first time, we have a goal, a clear goal that we're all working toward. ... Before we would just talk."

The commitment letters, which largely reaffirm previous pledges, were intended to get an idea of how far the nations most responsible for global warming might be willing to go, toward a legally binding pact at the climate conference planned for Mexico City at the end of the year.

China has pledged to reduce its emissions growth — not make absolute cuts — by up to 45 percent from 2005 levels by 2020. India also pledged to reduce emissions growth by up to 25 percent from 2005 levels by 2020.

The United States stuck to President Barack Obama's pledge to cut its absolute carbon emissions by about 17 percent by 2020 below 2005 levels.