Bali, Indonesia ? Two weeks of international climate talks marked by bitter disagreements and angry accusations culminated Saturday in a last-minute U.S. compromise and an agreement to adopt a blueprint for fighting global warming by 2009.

Now comes the hard part.

Delegates from nearly 190 nations must fix goals for industrialized nations to cut their greenhouse gas emissions while helping developing countries cut their own emissions and adapt to rising temperatures.

Negotiators also will consider ways to encourage developing countries to protect their rapidly dwindling forests – which absorb carbon dioxide.

“This is the beginning, not the end,” U.N. Secretary-General Ban Ki-moon told The Associated Press following the contentious climate conference, which stretched into an extra day. “We will have to engage in more complex, long and difficult negotiations.”

Those gathering on the resort island of Bali were charged with launching negotiations to replace the Kyoto Protocol, which expires in 2012. What they decide in the next two years will help determine how much the world warms in the decades to come.

In a series of pivotal reports this year, a U.N. network of climate and other scientists warned of severe consequences – from rising seas, droughts, severe weather, species extinction and other effects – without sharp cutbacks in emissions of the industrial, transportation and agricultural gases blamed for global warming.

To avoid the worst, the Nobel Prize-winning Intergovernmental Panel on Climate Change said, emissions should be reduced by 25 percent to 40 percent below 1990 levels by 2020. Greenhouse and other heat-trapping gases should be reduced at least by half by 2050.

When talks begin, the focus again will fall on the United States, the only major industrial country that did not accept Kyoto. That pact requires 37 industrial nations to reduce greenhouse gases by a relatively modest 5 percent on average in the next five years.

A turning point may come a year down the road following the U.S. election of a new president, who many environmentalists hope will support deeper, mandatory emissions cuts in contrast to President Bush, who favors only voluntary approaches to reining in greenhouse gases.