Being Green - what does it mean?

I was really honoured to be asked by two friends on separate occasions to be interviewed by the media on being green. In the end, due to other commitments, I had to decline but it got me thinking - what does green really mean?

Does it mean buying....

Or does it mean having an...

or....

or...

or having...

Hope I've got you thinking on how to be greener in life :-)