Harvey in 1997 led a local government delegation to Tahiti against French nuclear testing in the Pacific. In 1998 he joined the working party of the Mayor's Ascia Pacific Environment Summit and the following year was an executive member of that summit. Havey was a keynote speaker at Pathways to Growth at the invitation of British Prime Minister John Major in Manchester in 1993, at ICLEI(Local Governments for Sustainability) HABITAT 11 conference in Istanbal in 1995, at the Silicon Valley Environmental Conference in 2000 and at the American Water Works Association Conference in Hawaii in 2001. In 2002 Harvey was the Local Government representative at the United Nations World Summit on Sustainable Development (Rio+10) in Johannesburg. In 2007 he became a member of the Australasian Mayors for Climate Change and in 2008 was the keynote speaker at the Eco City Summit in Washington.