VIENNA, Austria - Negotiators from 158 countries reached basic agreement Friday on rough targets aimed at getting some of the world's biggest polluters to reduce emissions of the greenhouse gases blamed for global warming.
A weeklong UN climate conference concluded that industrialized countries should strive to cut emissions by 25 per cent to 40 per cent of their 1990 levels by 2020.
Experts said that target would serve as a loose guide for a major international climate summit to be held in December in Bali, Indonesia.
"We have reached broad agreement on the main issues,'' said Leon Charles, a negotiator from Grenada who helped oversee the Vienna talks.
Delegates worked into Friday evening to overcome resistance from several countries -- including Canada, Japan and Russia -- that had held up negotiations because they preferred a more open approach rather than setting emissions targets.
The 2020 targets are not binding, but they were seen as an important signal that industrialized countries are serious about slashing the amount of carbon dioxide and other dangerous gases to try to avert the most catastrophic consequences of global warming.
Friday's agreement sought to ease concerns that the emissions target might be too ambitious for some countries, noting that efforts to cut back on airborne pollutants are "determined by national circumstances and evolve over time.''
But it made clear that greenhouse gas emissions must be reduced to "very low levels'' to guard against potentially deadly flooding, drought and other fallout.
"Countries have been able to reassess the big picture of what is needed by identifying the key building blocks for an effective response to climate change,'' said Yvo de Boer, the UN's top climate official.
De Boer said the agreement doesn't let developing countries off the hook.
"Even if industrialized countries do this, it will only be a contribution to the global effort,'' he told reporters.
The Bali conference will try to forge a new global agreement to cut greenhouse gas emissions after 2012, when the 1997 Kyoto Protocol expires. The Kyoto accord requires 35 industrial countries to cut their emissions five per cent below 1990 levels by 2012.
Friday's agreement does not include the United States, which has not ratified the Kyoto Protocol.
Environmental groups stressed that developed countries need to take urgent measures to keep Earth's temperature from rising more than two degrees Celsius, a limit scientists contend is critical to prevent catastrophic flooding and other deadly weather patterns.
"They need to be guided by the potential calamity,'' said Angela Anderson, vice-president for climate programs at the Washington-based National Environmental Trust.
Failing to cut emissions by at least 30 per cent of 1990 levels by 2020 "would condemn millions to disease, water shortages and misery in the developing world,'' said Red Constantino, an official with Greenpeace International.
WWF International called Friday's agreement a "safe range for emission reductions,'' but cautioned that it would have to be put into action. "In Bali, they will have to formally adopt this,'' it said in a statement.
European Union officials had pressed hard for the 2020 targets. The EU already has pledged to cut emissions of carbon dioxide and other harmful gases by 20 per cent by that year, and by another 10 per cent if other industrialized countries join in.
Yvo de Boer, the UN's top climate official, said some developing countries, including small islands most vulnerable to climate change as polar ice caps melt and sea levels rise, were pressing industrialized countries for even deeper emissions cuts.
Their negotiators, he said, were acting out of a sense of urgency and a fear that "they won't have a country to represent'' if climate change is not slowed.
