DOHA, Qatar -- U.N. talks on a new climate pact resumed Monday in oil and gas-rich Qatar, where negotiators from nearly 200 countries will discuss fighting global warming and helping poor nations adapt to it.

The two-decade-old talks have not fulfilled their main purpose: reducing the greenhouse gas emissions that scientists say are warming the planet.

Attempts to create a new climate treaty failed in Copenhagen three years ago but countries agreed last year to try again, giving themselves a deadline of 2015 to adopt a new treaty.

A host of issues need to be resolved by then, including how to spread the burden of emissions cuts between rich and poor countries. That's unlikely to be decided in the Qatari capital of Doha, where negotiators will focus on extending the Kyoto Protocol, an emissions deal for industrialized countries, and trying to raise billions of dollars to help developing countries adapt to a shifting climate.

"We all realize why we are here, why we keep coming back year and after year," said South Africa Foreign Minister Maite Nkoana-Mashabane, who led last year's talks in Durban, South Africa. "We owe it to our people, the global citizenry. We owe it to our children to give them a safer future than what they are currently facing."

The U.N. process is often criticized, even ridiculed, both by climate activists who say the talks are too slow, and by those who challenge the scientific near-consensus that the global temperature rise is at least partly caused by human activity, primarily the burning of fossil fuels like coal and oil.

The concentration of greenhouse gases such as carbon dioxide has jumped 20 percent since 2000, according to a U.N. report released last week.

A recent projection by the World Bank showed temperatures are on track to increase by up to 4 degrees C (7.2 F) this century, compared with pre-industrial times, overshooting the 2-degree target that has been the goal of the U.N. talks.

Associated Press