In this time of crisis, thousands of papers and guidelines have already been published about COVID-19. Most of these consider the important questions of how to respond to the ongoing public health crisis, or how to mitigate the impacts of the pandemic. This report takes a step back and considers the root causes of the emergence and spread of the novel coronavirus and other 'zoonoses' - diseases that are transmitted between animals and humans. The report also offers a set of practical recommendations that can help policymakers prevent and respond to future disease outbreaks. Section 1: Overview of emerging infectious diseases including zoonoses -- Section 2: Coronaviruses in a One Health context -- Section 3: Understanding the linkages between habitat loss, the trade and use of wildlife, and the emergence of novel zoonoses -- Section 4: Managing and preventing zoonoses: how One Health can help -- Section 5: Preventing future zoonotic pandemics: What more could be done?