Zero? Human exhales like 2kg of CO2 every day. That is just 200kg of CO2 emmisions from existing!
> Preparations for this special challenge have been ongoing for many months. However, for a project like this to come together, a lot of things have to fit together perfectly.
Take all the people, time and energy spend on preparations! It is probably several tons of CO2! Very long list of sponsors!
I refuse to believe, that super economy flight for $130 has higher CO2 emmisions than this stunt! It is like taking public transport!