This article literally gives characteristics that you need to demonstrate. Really good.
This article on changing careers into green
Interesting: Linked In Research shows that one of five hire because of their volunteer work, so put that volunteer work on Linked In
This article also helpful in how to talk about and present yourself:
"Often the most important factor for breaking in is not the specific
qualifications you have but your ability to understand and bring together a
range of complicated issues, put these into business context and then
communicate them internally and externally.
Sustainability "is best done by an "insider" who knows the landscape and players already."
Doesn't advise taking a step down in career or returning to school. volunteer work is good.
Look for something specific "having a strategic and focused job role and sector target. You need to decide
exactly what you are selling and to whom."