ROME, July 6 (Xinhua) -- Leaders of the Group of Eight are expected to set goals on curbing greenhouse gas emissions during their three-day summit this week in L'Aquila.

    According to a draft declaration prepared by the G8 countries, emissions of world-warming gases would be cut by an "aspirational" 50 percent by 2050.

    The draft also urged a culmination of emissions by 2020 and then be significantly slashed to ensure that the rise of global temperatures would be below two degrees Celsius over pre-industrial levels.

    The G8 summit is considered a crucial opportunity for leaders of the world's most industrialized countries and emerging economies to make breakthroughs on a new global climate deal as a deadline draws nearer.

    The leaders of Britain, Canada, France, Germany, Italy, Japan, Russia and the United States will meet on the first day of the meetings. They then will gather with their counterparts from China, India, Brazil, Mexico and South Africa to discuss climate change and economic issues such as the supervision of international financial institutions.

    The 2007 Bali Roadmap set a two-year deadline for a global agreement on climate change and pledged to complete a new UN climate treaty at a Copenhagen conference in December to follow up on the Kyoto Protocol that expires in 2012.

    The leaders are expected to witness hard bargaining concerning climate change because of differences on the issue between developed and developing countries.

    The most industrialized nations are divided over how much emissions should be cut, which year to take as a base line, and how to help poor countries fight climate change.

    The European Union is targeting a 20-percent cut on greenhouse emissions over 1990 levels, while the United States favors a target 17-percent reduction by 2020 over 2005 levels, representing only a 4-percent decline over 1990 levels. The EU says the U.S. goal is not sufficient.

    Japan recently announced a plan to cut its emissions by 15 percent below 2005 levels by 2020, which translates into an 8-percent cut from 1990 levels. Australia set its emission target at 5 to 15 percent by 2020 compared to 2000 levels.

    Canada plans to cut emissions by 20 percent by 2020 on 2006 levels.

    The developed nations also want some wealthier emerging countries to set emission cut targets, a move that is strongly opposed by those countries.

    The environmental group Greenpeace urged the developed countries to shoulder more responsibility for tackling the climate change problem, saying that they are mostly to blame for global warming.

Special Report: President Hu attends G8 - emerging economies dialogue