(CNN) A 25-year-old New Zealand lawmaker giving a speech supporting a climate crisis bill was heckled by an older member of Parliament. Her witty response baffled her audience, to the delight of millennials everywhere.

Chlöe Swarbrick was speaking about the Zero Carbon Bill, which would set a target of zero carbon emissions for the country by 2050. When she was heckled, she casually dropped a sharp-tongued retort — "OK boomer" — and, unfazed, continued talking amid the puzzlement and silence of the room.

The term, a viral meme among millennials and Generation Z, exploded this year on the TikTok social media app, where countless mocking videos are calling out what young people perceive as out-of-touch Baby Boomers and their patronizing opinions.

An article on the New York Times calls the "OK boomer" phenomenon "a rallying cry for millions of fed up kids." T-shirts and hoodies with the phrase have appeared on online marketing sites.

Swarbrick, a Green Party MP, was explaining Tuesday how the climate emergency will affect her generation and the generations to come, when she was interrupted by a heckler.

"Mr. Speaker, how many world leaders, for how many decades have seen and known what is coming but have decided that it is more politically expedient to keep it behind closed doors. My generation and the generations after me do not have that luxury," she said. "In the year 2050, I will be 56 years old. Yet, right now, the average age of this 52nd Parliament is 49 years old."

That's when she was heckled about her age, prompting her to reply, "OK boomer" without missing a beat, according to the Parliament's video of the speech. In the video, a man sitting behind her chuckles at her put-down.

Swarbick said later in a Facebook post that people were upset about her remarks.

"Today I have learnt that responding succinctly and in perfect jest to somebody heckling you about *your age* as you speak about the impact of climate change on *your generation* with the literal title of their generation makes some people very mad," she wrote. "So I guess millennials ruined humor. That, or we just need to pull ourselves up by our bootstraps and abstain from avocados. That's the joke."

In a text-message conversation with New Zealand's Stuff, Swarbick explained the phrase is a "simple summarisation of collective exhaustion."

She added that she was tired of hearing that millennials ruined everything, and they need to "pull our socks up, or something." Swarbick went on to acknowledge that "you cannot win a deeply polarized debate - facts don't matter."

"It's better to acknowledge that perhaps energy is better spent elsewhere," she said. "That rallying cry is the relatively innocuous 'okay boomer'."

New Zealand's Parliament TV wasn't in on the joke, either. Its closed captioning transcribed the Swarbrick's retort as "OK, Berma." The parliament's social media team later issued an apology.

"We apologise for the error, and have updated the captions accordingly. Clearly we need to start doing all-office meme briefings," it said in a tongue-in-cheek tweet.