Africa, the continent hardest hit by global warming, ended its boycott of the United Nations climate-change talks in Barcelona after developed nations promised to reduce more greenhouse gas emissions.

Representatives from more than 50 African nations agreed on Tuesday to return to the negotiating table about a post-Kyoto Protocol deal after they were assured that 2020 targets on emission cuts would be re-evaluated. The Kyoto Protocol will expire in 2012.

"We were able to arrive at a solution," John Ashe, an official from Antigua and Barbuda, told delegates at the 175-nation meeting.

African countries reportedly didn't attend discussions earlier on Tuesday, the second day of the last round of formal negotiations before the UN Climate Change Conference in Copenhagen. They claimed that developed countries are not taking 2020 targets of greenhouse gas emission cuts seriously enough.

African countries are the worst hit by global warming, the reason they initiated the boycott, said Wang Ke, a researcher from Beijing-based Renmin University of China.

"They are the most innocent victims of climate change," Wang said. "They emit very little amount of greenhouse gases, but they suffer the most from the impending climate disaster."

Representatives from African nations said climate change is likely to trigger floods, droughts, heat waves and rising sea levels, all of which will create more famines and water shortages in Africa.

Scientists said industrial countries should reduce emissions by 25-40 percent from 1990 levels by 2020, but the current cuts developed nations are offering range from 11 percent to 15 percent.

Despite the effective boycott, some Chinese experts said the maneuver is not likely to affect the negotiation progress because Africa does not play a "dominant position" in the climate talks.

The Barcelona climate-change talks are dominated by the European Union, the United States and several other developed countries, such as Japan and Australia, as well as major emerging developing countries, such as China and India.

Zou Ji, World Resources Institute's China director, said the move suggests that African countries are very dissatisfied with the climate-change negotiations.

"(The boycott) is a signal that no substantial compromise has been made from any countries up until now although the UN climate talks in Copenhagen is just a month away," Zou said.

Greenpeace USA Climate campaign director Damon Moglen blamed the indifference on the US, the world's largest emitter of greenhouse gases.

"While the US Congress is squabbling about which subsidies to give to the fossil fuel industry and other ways to justify climate inaction, the Africans are talking about their survival," he said.

"(US) President (Barack) Obama can no longer hide behind failed congressional legislation. He must provide ambitious, science-based emissions reductions targets," Moglen said.