The 2015 post saw her use the hashtag “cloud land” from 30,000 feet, with another in 2018 entitled “Nepal” showing her standing among snow-capped mountains.
Speaking to Express.co.uk, Ms Rumbelow said she last travelled by aeroplane in 2019, and has sworn off the mode of travel since then.
She clarified that other trips taken to Europe and any made since then were undertaken via rail or hitchhiking.
But the revelations as they were first reported by the Daily Mail have led to significant online pushback.
She has been labelled a “hypocrite” by Britons following her dramatic exchange with Mr Austin on Thursday.
Ms Rumbelow appeared on his show as a Just Stop Oil spokesperson to speak about the activist group’s tactics.