Given the urgency of mitigating global warming and climate disruption with the consequent impacts on health and wellbeing, all avenues for the public health movement to drive action to mitigate and adapt to these threats need to be explored. This project investigated the legislated powers granted to Australian public health medical officers (PHOs) to protect health through actions to limit fossil fuel use. A review of Australian state and territory Public Health Acts was undertaken to ascertain the scope for PHO’s intervention in curtailing fossil fuel use, unconventional gas extraction, and coal mining and burning on public health grounds. Powers exist in the acts which public health officers could use to protect the public’s health from climate disruption. Secondly, this project sought international comparisons of public health agencies using their powers reduce pollution and coal/gas use. The implications of these examples for Australia are discussed. Finally, the Report suggests some areas and action that PHOs might take to exercise their powers to protect and promote the public’s health from greenhouse gas emissions, global warming and climate disruption. We leave it to our current public health medical officers to decide how they want posterity to judge them on this issue.