Greta Thunberg lashed out at international leaders at climate talks in Italy on Tuesday (September 28).
At the Youth4Climate event, she said much had been promised to tackle global warming, but little done in the decades after the landmark Earth Summit.
"There is no planet B, there is no planet blah, blah blah blah, blah blah blah. This is not about some expensive, politically correct, green act of bunny hugging or blah blah blah. Build back better, blah blah blah. Green economy, blah blah blah. Net zero by 2050, blah blah blah. // Our hopes and dreams drown in their empty words and promises. Of course we need constructive dialogue, but they have now had 30 years of blah blah blah and where has that led us?"
Thousands of young activists converged on Milan this week - some 400 from around 190 countries.
They're set to engage with policymakers in the hope of hammering out possible solutions.
"They invite cherry-picked young people to meetings like this to pretend that they are listening to us. But they are not. They are clearly not listening to us, and they never have. Just look at the numbers, just look at the statistics. The emissions are still rising. The science doesn’t lie."
The youth activists have fought to get climate change to the top of the global agenda for years.
They are now being challenged to help come up with the solutions ahead of the COP26 United Nations summit in Glasgow in November.
Their proposals will be vetted by climate and energy ministers gathering for their pre-COP26 meeting, which kicks off on Thursday (September 30).
Ugandan youth delegate Vanessa Nakate was comforted by Thunberg after demanding that world leaders take action.
"It's time for our leaders to stop talking and start acting, it is time to start the real costs and it is time for the polluters to pay. It is time to keep their promises, no more empty promises, no more empty summits, no more empty conferences. It is time to show us the money, it's time, it's time, it's time and don't forget to listen to the most affected people and areas."
The U.N. COP26 conference aims to secure more ambitious climate action from the nearly 200 countries who signed the 2015 Paris Agreement.
Climate activists are demanding policymakers put their money where their mouth is, and stump up the billions of dollars needed to wean the world off fossil fuels to cleaner energy.
Fears that climate change is worsening grew after a U.N. report in August warned the situation was dangerously close to spiralling out of control.
It added that the world would certainly face further disruptions for generations to come, during a year that has seen record-breaking heatwaves, floods and fires.