GENEVA, June 23 (Xinhua) -- Former United Nations chief Kofi Annan on Tuesday urged developed countries to take the lead in tackling the crisis of climate change, which he called "the greatest environmental and humanitarian concern of our age."

    "There must be deep, binding and fair targets to cut emissions of greenhouse gases. Those developed economies most responsible for past and present emissions must take the lead," Annan told a forum in Geneva.

    "Without them accepting responsibility, the rapidly developing economies will understandably resist the changes in their economies which are also needed," he said.

    The Global Humanitarian Forum was established by Annan in 2007,following his retirement from the top UN post. The second annual meeting of the Forum opened on Tuesday, focusing on the human impact of climate change.

    "The polluter-must-pay principle should be put into practice locally, nationally and internationally to help fund mitigation and adaptation measures," Annan told experts and officials attending the two-day meeting.

    "This must include a transfer of additional resources, and technology to help developing countries protect their citizens and grow their economies sustainably," he said.

    According to the 71-year-old former UN chief, climate change will be "a major brake on development hopes" in the coming years and decades.

    It is the poorest countries and poorest people who are suffering most from climate change, although they have done least to cause this crisis, he said, adding this is a "deep injustice."

    He said the new president and new administration in the United States had demonstrated their seriousness about combating climate change, which "raises optimism" for a new deal in Copenhagen in December.

    More than 190 countries are expected to meet in the Denmark capital to find a successor to the Kyoto Protocol, which regulates emissions of greenhouse gases.

    "There is no doubt that the decisions they make at Copenhagen will help shape the world we leave to future generations," Annan said.

    "But we must all accept our responsibilities as well -- as leaders within our organizations but as individuals, parents, as consumers and citizens, too," he said.