Brazil president opens Rio+20 summit with call to act

The UN Conference on Sustainable Development opened Wednesday, launching a new round of debate on the future of the planet, its resources and people, 20 years after the first Earth Summit. Opening the so-called Rio+20 Summit, Dilma Rousseff, president of host nation Brazil, called on \"all countries of the world to commit\" to reaching an accord that addresses serious environmental and social woes. The UN conference, which marks the 20th anniversary of the Earth Summit that declared the environment a priority, is the largest ever organized, with 50,000 delegates, the United Nations said. Around 115 leaders are expected for the summit itself on June 20-22 but a series of business, environmental and nongovernmental organization conferences are being held in the runup. This frenzy of contacts and deal-making could well be more fruitful than the UN process itself, say some, mindful of the failures of the 2009 climate summit in Copenhagen. Still it is hoped that the leaders can seal a deal that has been in the works for three months but with two-thirds of proposals still lacking consensus. The United Nations itself has not ruled out the possibility of intense negotiations continuing right up to the June 20-22 leaders summit that will be attended by French President Francois Hollande and China\'s Prime Minister Ben Jiabao, and others. Notably absent from the summit will be US President Barack Obama, who is facing a tough presidential re-election race at home, and German Chancellor Angela Merckel, whose country in the past has shown extraordinary commitment to environment issues. A report released ahead of the gathering described an urgent need to tackle population growth and voracious consumption that are placing Earth\'s resources under intolerable strain.