Indo-Asian News Service: The Delhi Metro, which is the first railway project in the world to be registered for carbon credits by the United Nations, has been certified to have prevented over 90,000 tonnes of carbon dioxide from being released into the atmosphere by reducing its power requirement in three years, an official said Sunday. Registering the Delhi Metro’s contribution, the Germany-based validation organization TUVNORD conducted an audit on behalf of the UN Framework Convention on Climate Change …