COCHABAMBA, Bolivia — Environmental activists, indigenous leaders and Hollywood celebrities are gathering in Bolivia ahead of a self-styled global people's conference on climate change starting Tuesday. Thousands of attendees intend to highlight the plight of the world's poorest who they argue were largely ignored at the official United Nations-sponsored summit in Copenhagen last December. The Copenhagen meeting was widely drubbed for failing to produce a new treaty to limit greenhouse gas emissions, with Bolivia, along with Cuba and Sudan, among the leading voices questioning the climate accord. Critics say that deal will not avert a catastrophe and the "People's World Conference on Climate Change and Mother Earth Rights," which runs through Thursday, aims to draft new proposals for consideration at the next UN meeting in Mexico at the end of the year. Bolivia's UN ambassador Pablo Solon said the conference, which was expected to be attended by some 18,000 people.