Carbon neuter me

I'm thinking about making my life carbon neutral. All of it.
I went onto the website today (www.carbonneutral.com.au) and they have some kind of rudimentary calculator on there which tells you how much carbon you're responsible for billowing into the atmosphere each year. You then make a donation and that is used to plant trees which offset your emissions.
I did a story on carbon neutral when I was working for How The Quest Was Won on the ABC. It seemed like a good idea. That was just to offset your car emissions, but this calculator can offset everything - house, car, air travel, etc.
Well I've always been a bit green - though not as green as I could be - and despite Grandma making me plant literally hundreds of trees on the farm as a kid, I think I can do more.
So I'm thinking I could plant enough trees to cover my carbon emissions for my entire life to-date. Only I have to calculate how much that would cost. It may not really be feasible.
But then, how feasible is selfishly using and not replacing the planet's resources willy-nilly and irresponsibly?
Yes, dear friends, if I do this I am going to be the smuggest bitch you've ever met in your whole life.
I'll keep you posted.