Before entering parliament, John taught and researched electrical engineering at the University of NSW where he specialised in sustainable energy and greenhouse issues. John has a PhD from the University of California Berkeley and over twenty years of research and teaching experience. He has been a vocal critic of electricity industry privatisation and a strong advocate for renewable energy and energy efficiency.

John has also worked as a volunteer, spokesperson, campaign coordinator, parliamentary policy adviser and candidate for The Greens, including:

Lead Senate Candidate, 2004 Federal Election. The Greens vote increased by a massive 30 per cent in a tightly contested election in which preference allocations by the ALP and the Democrats favoured right wing and religious extremists over The Greens. While he was not elected to the senate, the highly energetic campaign contributed to the development of The Greens as a major political force.
Greens Campaign Coordinator, 2003 State Election. The Greens vote trebled in one of our most successful and well organised campaigns yet. We made history by electing both Ian Cohen and Sylvia Hale to the Legislative Council. John played a key role in developing and implementing our innovative and determined approach that made voters take notice of our optimistic vision for forests, public education, the urban environment and drug law reform.
Policy Adviser to Lee Rhiannon's Parliamentary Office, 1999-2002. Lee's office put the corrupting influence of developer donations to the major parties on the national agenda. As a team, we built a strong reputation as campaigners for public education, sustainable transport, the urban, rural and natural environments and workers' rights.
Greens NSW Policy Coordinator, 1998-2001, 2003. Working with local groups, and drawing on a deep knowledge and understanding of Greens' principles, processes and issues, John coordinated the development of leading edge policies that have served us well in elections.
Greens Education Spokesperson, 2000 – present. Our highly successful campaign in support of public schools, TAFEs and public universities has directly contributed to the lowering of class sizes and to the debate on private school funding. This work is attracting considerable media coverage and community support and has established the Greens as a respected voice for public education.
Greens Candidate for Federal, State and Local Government, 1997-2004. As an experienced candidate and spokesperson, John has been a strong media performer and public speaker. He has also served in key campaign coordination positions in federal, state and local elections and have worked closely with Greens groups and candidates across NSW and Australia.
Environment and Transport Campaigner, 1984 – present. John continues to be a key player in numerous campaigns to protect the environment from developers and road builders, including frequent Land and Environment Court appearances in support of communities under attack.