Climate change protester Rosemary Penwarden, a 64-year-old retired medical scientist, was sentenced to 125 hours’ community work in October after a jury found her guilty of creating and using the false document.
Ms Penwarden said afterwards "we grandmothers won’t be silenced.
"We have got to start standing up together and be loud and be brave and be bold."
The case could not have given the climate cause better publicity if it had been paid for, she said.
In September 2019, 12 days before the Petroleum Exploration and Production Association of New Zealand (PEPANZ) conference went ahead at Queenstown’s Millennium Hotel, she used a friend’s laptop to draft a letter.
Using PEPANZ letterhead and industry logos, it explained the event was postponed because of the expected disruption from protesters.
Conference organisers worked hurriedly to reassure attendees the event remained on schedule and it eventually proceeded as planned.
At trial, Ms Penwarden said it was simply satire, and she had been surprised to be charged for the incident the following year.
"You have a bit of fun doing that and it’s a form of protest."
The judge denied her application for discharge without conviction, saying she must be deterred from behaving in an illegal way in the future.
"She lacks insight into her behaviour and shows no remorse," he said.
Ms Penwarden was also arrested in August after a group of protesters used a substance to affix themselves to a Wellington road.
She was charged with endangering transport, a case that has not yet come to trial.
She was originally declined release in the Wellington District Court before being granted electronically monitored bail less than a fortnight later by the High Court.
