I'd say Shawna and I have been tick tacking on sustainable events for more than a decade. I remember connecting with her when I first wrote my books.
She truly was a beacon in those early days. She totally got it. At last I'd found my person! I'm constantly impressed by Shawna's insights and how about her most recent offering, the carbon calculator for digital events.
Check it out here: https://digitaleventcarboncalculator.com/