How to indicate career change (from environmental to entertainment) when applying for jobs?

I have a masters degree from Harvard in environmental sciences and I really dont want to work in this field anymore. At least not directly. Most of my experience is related to sustainability and remediation and environmental policy as well as envrionmental health sciences and I just dont wanna do it anymore. It is dull and boring. I want a career in the entertainment industry in either PR, communications, marketing, writing, producing....I am an excellent writer and if you can promote environmental issues, you can promote anything.



I am really into the movie industry and I know just a lot about it, but I dont have any formal training in it or any experience.



My main question is, when I do find a job in PR that i wanna apply to...how should I go about indicating my desire to change careers in the cover letter? How do I explain my desire to apply for a position ,given my totally different background ? Do I just flat out say I am looking to change tracks? That I want to change my career path? What exactly do I say? I mean there must be people out there who do that right? Changing careers. I just graduated so it is not like i am all settled in my ways. But how do I bring that across? I really need to get away from what I am doing and i really love the eterntainment world,and writing and the creative process.How to indicate career change (from environmental to entertainment) when applying for jobs?
well maybe do your master in PR (communications) and you can work for an enviormental company in the communications dept...so a little of both ..I actually want to read the answers to this one..IS great question.