When 16-year-old climate warrior Greta Thunberg spoke at the United Nations (U.N.) on September 23, she gave a room full of world leaders, in New York City to participate in a summit on climate change, a dressing down for their inaction.
"This is all wrong," she stated, her voice trembling.
"I shouldn't be up here. I should be back in school on the other side of the ocean, yet you all come to us young people for hope."
Then came the battle-cry heard around the world, three words that were soon trending worldwide: "How dare you."
The tremendous impact of Thunberg's speech was only further amplified by footage and photographs depicting the young activist giving an all-time death stare to US President Donald Trump, a , in what some are calling "the photo of our times."
On social media, users expressed a mix of pride, admiration, shame and frustration - with an underlying consensus that Thunberg's speech will be looked back on as a historic moment.
One Twitter user wrote: "Martin Luther King said 'I have a dream', Kennedy said 'Ich bin ein Berliner', Reagan said 'Tear down that wall', Obama said 'Yes, we can'. said 'How dare you?'. This is history!"
Others felt more helpless.
"Just after the speech, I cried," one tweeted.
"Because that's what I think, that's what I feel, that's what every child who has understood the urgency feels. Fear, anger and helplessness."
While the U.S. will not be participating in the U.N.'s climate summit, China and roughly 70 other countries are expected to make announcements concerning further action on climate change.
The summit followed a worldwide Youth Climate Strike on Friday, which saw millions of young people around the world - including in every major Australian city - demanding action to address the climate crisis.
