The U.S. never joined the Kyoto accord, while Japan, New Zealand, Canada and Russia don't want to be part of its extension, meaning it would only cover about 15 percent of the world's emissions of greenhouse gases.
Governments have set a deadline of 2015 to agree on a wider deal that would include both developed and developing countries, which now produce a majority of the world's emissions. As part of that, delegates were also trying to make progress on the 2015 work plan and close loopholes that would bring all countries into one negotiating path.
On paper, these issues seemed routine.
But throughout the day, countries took advantage of these meetings to fight over a wide range of issues that included technology transfer to poor, emission commitments by rich countries in the next eight years as well as a demand from Saudi Arabia to discuss ways of helping countries diversify their economies under a new deal.
The Chinese were among the most vocal, at one point trying to insert language into the text that backtracked from the agreement in Durban that requires both rich and poor countries to take binding action to combat climate change when a new deal is set to take effect in 2020.
"We're doing ridiculous things," Chinese delegate Su Wei said, before backing off his demand.
The negotiations were also hampered, delegates and activists said, by a lack of leadership from Qatar. Draft agreements were not ready until the last second and Qatar did nothing to bring together key ministers to hash out a grand deal as past presidents have done.
Still, the talks remained alive and nobody was talking of walking away from the table.
The goal of the U.N. talks is to keep temperatures from rising more than 3.6 degrees Fahrenheit (2 Celsius), compared to preindustrial times. Temperatures have already risen about 1.4 degrees Fahrenheit (0.8 Celsius) above that level, according to the latest report by the U.N.'s top climate body.
A recent projection by the World Bank showed temperatures are on track to rise by up to 7.2 Fahrenheit (4 Celsius) by the year 2100.
"There is a huge lag between the international policy response and what science is telling us," U.N. climate chief Christiana Figueres told The Associated Press. "We know that science tends to underestimate the impacts of climate, and so if anything, that gap continues to grow."
AP reporter Karl Ritter contributed to this report.
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