At a high-level event on Wednesday at the United Nations climate summit, Swedish teen climate activist Greta Thunberg slammed world leaders for “misleading” the public with insufficient emission-reduction pledges and dove into the growing science that shows governments must act quickly to prevent catastrophic warming. 

Thunberg kicked off her speech at the 25th Conference of the Parties, or COP25, by telling world leaders that she wouldn’t have any personal or emotional headline-grabbing one-liners, like when she told world leaders she wanted them to panic.  

“I will not do that, because then those phrases are all that people focus on,” she said. “They don’t remember the facts, the very reason why I say those things in the first place. We no longer have time to leave out the science.” 

Thunberg highlighted numbers from last year’s sobering report from the Intergovernmental Panel on Climate Change, the leading United Nations consortium of researchers studying human-caused temperature rise. It found that to have a 67% chance of keeping the global temperature from exceeding 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels ― the aspirational goal of the Paris climate agreement ― the world can only emit 570 gigatons of carbon dioxide. Studies show we are on track to blow past that carbon budget within a decade, and that meeting the 1.5-degree target requires cutting global emissions 7.6% every year from 2020 to 2030. 

“How do you react to these numbers without feeling at least some level of panic?” Thunberg asked a room full of delegates and others gathered at the summit. “How do you respond to the fact that basically nothing is being done about this without feeling the slightest bit of anger?”

Thunberg noted that 100 companies are responsible for 71% of greenhouse gas emissions, and that since the Paris agreement, global banks have invested $1.9 trillion in fossil fuels. She accused political leaders from rich countries of “misleading” people about the crisis and “finding clever ways around having to take real action,” including outsourcing emissions overseas to poorer countries and refusing to compensate vulnerable nations for climate-related damages.

The U.N. climate talks, she said, “have turned into some kind of opportunity for countries to negotiate loopholes and to avoid raising their ambition.” 

She continued:

The biggest danger is not inaction. The real danger is when politicians and CEOs are making it look like real action is happening, when in fact almost nothing is being done, apart from clever accounting and creative PR.

In just three weeks, we will enter a new decade ― a decade that will define our future. Right now we are desperate for any sign of hope. Well I’m telling you there is hope, I’ve seen it. But it does not come for the governments or corporations. It comes from the people. 

Wednesday’s “High-Level Event on Climate Emergency” also included speeches from Jennifer Morgan, the executive director of Greenpeace International, and Hilda Flavia Nakabuye, a youth climate activist from Uganda. As the panel discussion came to an end, dozens of young activists from the Fridays for Future movement stormed the stage, where they chanted and staged a sit-in to demand immediate action. 

“We need leadership on climate action, not talks,” an emotional Nakabuye said. “You’ve been negotiating for the last 25 years, even before I was born. Do you want the whole of Africa to first perish before you start acting?”