Agence France Presse: Tony Blair on Saturday urged the world’s heaviest polluters including the United States, China and India to agree to binding emissions cuts, saying failure to act on global warming would be "unforgivably irresponsible." But disagreements were out in the open as the former British prime minister took on his new role as a mediator trying to help all sides meet a deadline to draft a successor treaty to the Kyoto Protocol by the end of next year. "We have reached the …