President Barack Obama on Monday put his administration on a course of environmental activism, discussing eco-friendly initiatives he is pursuing and taking several not-so-subtle potshots at his predecessor. “I want to be clear from the beginning of this administration that we have made our choice,” said Obama, who spoke in the East Room of the White House. “My administration will not deny facts — we will be guided by them,” he declared. “We cannot afford to pass the buck or push the burden onto the states.” Obama urged passage of the economic stimulus bill, which includes spending on emissions-reducing technologies. He said new tailpipe standards for automobiles will begin to be implemented in model year 2011 and announced that he was speeding consideration of a waiver that would allow California and other states to set their own emissions rules. Obama said deteriorating economic conditions mandated fast action on the stimulus. “We can’t afford distractions and we cannot afford delays,” he said.