A New Zealand lawmaker responded to an older colleague's heckling on Tuesday by using the phrase "OK boomer" during a speech about climate change.

Chlöe Swarbrick, 25, was speaking in Parliament during a debate over a proposed Zero Carbon bill, which would set a target of zero carbon emissions for New Zealand by 2050.

"In the year 2050 I will be 56 years old," Swarbrick said during the speech. "Yet, right now, the average age of this 52nd parliament is 49 years old."

As she spoke, another member could be heard making noise in response to Swarbrick talking about her age.

Without hesitation, Swarbrick remarked, "OK boomer."

The video of Swarbrick using the phrase has gone viral, with news outlets around the world sharing the clip.

The phrase "OK boomer" has become a catch-all among Gen Z and younger millennials to push back against the criticisms of older generations. The term marks a boiling point among young people, who are frustrated with older generations' inaction on issues, especially climate change.

"OK boomer" has appeared across social media, but it is most prolific on the short-form video app TikTok.

When asked by a reporter what the phrase "OK boomer" meant to her, Swarbrick said it was an expression of frustration.

"It's kind of a unintentionally crowd-sourced explanation of frustration summarized in one symbolic, swift sentence," Swarbrick said. "I think I can probably claim the first MP across the world [to use 'OK boomer'] so we'll go with that, mate. New Zealand's world-leading in multiple ways today."

Swarbrick later wrote on Facebook, acknowledging that her speech had upset some people.

"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."

But despite upsetting some of her colleagues, on Thursday, New Zealand lawmakers passed the Zero Carbon bill.

The bill would require all greenhouse gases except methane from animals to be reduced to net-zero by 2050, according to the Associated Press. Methane emissions would be reduced by 10 percent by 2030 and by between about one-quarter and one-half by 2050, the AP reported.