This is more important than knowing what you are talking about. (Listen to a good political orator!)
People in functional units in the organisation are often dedicated to their own objectives and targets, and dismissive of externally imposed changes.
Environment can be a bigger cause of concern than other business areas, because of
- fear of being found out to be in breach of environmental legislation
- anger at industrialists because of their degradation of the planet
- delight that the organisation is going to do something to manage its environmental impacts.
Get to know your audience and communicate with them, not at them. Channel their emotions into making a beneficial difference.