As delegates worked long hours in search of a climate compromise by Thursday, the European Union on Tuesday added fuel to the diplomatic fire between China and the United States — saying that neither country's climate targets are aggressive enough.
"We expect them both to raise ambition level," EU environment spokesman Andreas Carlgren said of the U.S. and China. "Otherwise we won't be able to reach the 2 degree target."
The U.S., for one, signaled that would not be happening. It was, however, dispatching Secretary of State Hillary Rodham Clinton, a State Department source said Tuesday. She is expected to arrive Thursday, a day before President Barack Obama.
Many scientists have warned that the commitments so far fall short of what is needed to keep global temperature increases below 2 degrees C (3.6 degrees F) above pre-industrial levels and head off the worst of global warming.
The Obama administration has set as its target a 17 percent reduction from 2005 emissions levels by 2020. That amounts to a 3 percent to 4 percent cut from 1990 levels — the baseline year used by many other countries.
China has pledged to cut "carbon intensity" — a measure of carbon dioxide emissions per unit of production — by 40 percent to 45 percent by 2020, compared with 2005 levels.
Since China's economy is expected to double in size in coming years, that pledge means China's emissions will still increase, but instead of doubling they'd be checked at a nearly 50 percent increase.
The European Union, on the other hand, has promised to reduce its emissions by at least 20 percent of 1990 levels by 2020 — and go up to 30 percent if others make comparable commitments. Japan and Russia have already promised 25 percent cuts.
U.N. chief: 'Stop pointing fingers
Since the start of talks last week, China and the United States — the two largest emitters of carbon dioxide — have been waging a war of words.
China accused the United States and other rich nations of backsliding on their commitments to fight global warming, and the top American envoy declared the U.S. would not change its offer on emissions cuts.
Trying to ease the tensions, U.N. Secretary-General Ban Ki-moon on Tuesday said rich and poor countries must "stop pointing fingers" and should increase their pledges.
The U.S. delegation has its hands tied, however, since Congress has not passed legislation setting reductions.
U.S. special climate envoy Todd Stern defended the Obama administration's emissions-cutting target as "equal to or higher" than most of what the EU is proposing, and said the United States won't offer new numbers at the talks.
"I'm not anticipating any change in the mitigation commitment," he said. "Our commitment is tied to our anticipated legislation."
The House in June passed a bill with the 17 percent target. The Senate is discussing a similar bill, but it is not expected to come for a vote for several months.
Ban's warning in an interview with The Associated Press came as some world leaders began arriving in the Danish capital, kicking the two-week conference into high gear.
Obama and Chinese Prime Minister Wen Jiabao are among more than 110 world leaders expected in Copenhagen by week's end.
U.S. vs. China
China and other developing countries are resisting U.S.-led attempts to make their cuts in emissions growth binding, instead of voluntary, and open to international scrutiny.
China is grouped with developing nations at the talks, but the U.S. doesn't consider China to be in need of climate-change aid.
"You can't even begin to have an environmentally sound agreement without the adequate, significant participation of China," said Stern.
In Beijing, China accused developed countries Tuesday of trying to escape their obligations to help poor nations fight climate change. China believes the U.S. and other rich nations have a heavy historical responsibility to cut emissions, and that any climate deal should take into account a country's development level.
"We still maintain that developed countries have the obligation to provide financial support," Foreign Ministry spokeswoman Jiang Yu said, adding that was "the key condition for the success of the Copenhagen conference."
The U.N. conference's working groups were finishing up two years of work and drawing up their final recommendations on such issues as deforestation, technology transfers and the registration of plans by developing countries to control their emissions.
Drafts on those issues showed some narrowing of gaps but left many disputes to be decided by environment ministers, which ultimately may go up to the heads of state.
"Ministers have to be very clear and focused over the next 48 hours if we are to make it," said conference president Connie Hedegaard of Denmark.
She hoped the tight deadline might add urgency to the talks and help break the deadlock.
"It's just like schoolchildren," she said. "If they have a very long deadline to deliver an exercise they will wait for the last moment ... it's basically as simple as that."
Talks on a global climate deal hit a snag Monday when developing countries walked away temporarily from the negotiations, fearing industrial countries were backpedaling in their promises to cut greenhouse gases.
The issues concern the details of a final treaty to be negotiated in the next six to 12 months and may not even be included in the political deal reached in Copenhagen.
India's environment minister, Jairam Ramesh, said the talks could even break down on "serious" outstanding issues. "There is confusion and lack of clarity at this stage," he said. "There could be breakdown on many issues. We still don't have great clarity on how the next few days are going to evolve."
One thorny issue is how far developing nations should be bound to targets to slow their growth in emissions, a process known as measurement, reporting and verification (MRV).
"The MRV issue is a very serious divider," said Ramesh. The issue "might not sound that sexy but its still a very crucial part because that is where there are red lines to different parties," said Hedegaard.
Business leaders have said they want a clear deal with short and long-term targets so that they can invest appropriately.
"There are still lots of issues that will likely be discussed only at the ministerial level, and that gives us some cause for concern," said Abyd Karmali, global head of emissions trading at Bank of America Merrill Lynch.