Don’t just invite people to make up the numbers! Choosing carefully will help reduce the environmental impact from travelling, invitations, and food and drink preparation.
Encourage your guests to carshare when going to the wedding or evening reception. Try not to have a really isolated venue, only adding to eveyone's travelling emissions, etc.
Make use of local resources wherever possible. If you choose to use disposable items, plates etc, use organic-based disposables like corn based plastic and sugar cane plates.
Hire a photographer who uses recycled paper for his photos and albums.
Choose a venue that takes an active approach to recycling and other environmental issues.
Use green transportation when it comes to getting yourself to the church. Of course a horse and carriage is a wonderful idea, but you can just as easily arrange a hybrid car these day's.
However you decide to hold your wedding, just make sure that you are comfortable with your wedding plans. Inevitably there may be issues out of your control on the day, so don't fret too much if Auntie Mabel turns up in her new Range Rover...just make the most of your very special day.