If your staff do not already understand Sustainable Development and how that can be translated to the event planning cycle, yes they will need to be trained. There are different aspects for different staff members, depending on their role. The person that is charged with the task of setting up the events sustainability management system will need to have a thorough understanding of management systems, event planning and sustainability. Others, such as a site manager, production manager, waste manager etc, will need to understand the practical application of the goals and objectives of the management system as it relates to the aspect of the event they are in control of. Induction may be enough training for some staff, others may need to attend a course, alternatively a consultant could be brought in during a live event planning cycle to walk the team through the options. This is not brain surgery, it is just setting up a way of thinking and ensuring the team have access to the relevant and up to date information on sustainability in event management.