A former political adviser, lobbyist and speechwriter, Guy grew up in Townsville and was educated at James Cook University (BA Hons), Harvard (MPP), and the ANU (PhD). He was a member of the Liberal Party for 19 years and worked for various Liberal politicians including former environment minister, Robert Hill. He has been government relations and policy adviser for numerous industries and environmental organisations, and a consultant to the Australian Greenhouse Office. While studying at the Kennedy School of Government and Harvard Business School in the mid 1990s, Pearse also worked on the advance staff of then US Vice President, Al Gore.
Guy's doctoral research (1999-2005) uncovered damning evidence of the influence of the carbon lobby on the Howard government--including admissions by lobbyists that they were writing cabinet submissions and ministerial briefings that ought to be written by public servants. Having raised his growing concerns about this influence and the direction of Australia's greenhouse response with senior figures in the Howard government to no avail, Guy decided the public interest in an urgent response to climate change was more important than his then partisan affiliation, his plans for a political career and his comfortable living as a lobbyist.
His thesis became the basis for the "Greenhouse Mafia" episode of ABC's Four Corners in February 2006.
In 2007, Guy exposed the dirty politics behind Australia's response to climate change in much greater detail in High & Dry: John Howard, climate change and the selling of Australia's future (Penguin--2007). In the 2007 election campaign that saw the Liberal Party defeated, he openly campaigned against the Howard government on the basis of its greenhouse policies. Having seen the Rudd Labor government embrace policies that double coal exports and allow greenhouse pollution in Australia to grow for at least another decade, he wrote Quarry Vision: Coal, climate change and the end of the resources boom (Quarterly Essay 33)(Black Inc--2009).
He continues to advocate a much stronger response by Australia to climate change.