 The Conservatives withdrew Canada from the Kyoto Protocol in December 2011.On October 10, 2006 in Vancouver, Harper announced tougher measures than the previous Liberal government such as tax credits to environmentally friendly measures, a repackaged air quality health index and a program to retrofit diesel school buses.Harper mentioned that these measures would "move industry from voluntary compliance to strict enforcement; replace the current ad hoc, patchwork system with clear, consistent, and comprehensive national standards, and institute a holistic approach that doesn't treat the related issues of pollutants and greenhouse gas emissions in isolation."