Swedish activist gives passionate speech addressing world leaders at UN Climate Change Summit

UNITED NATIONS -- Leader after leader told the United Nations on Monday that they will do more to prevent a warming world from reaching even more dangerous levels. But as they made their pledges at the Climate Action Summit, they conceded it was not enough.

Sixty-six countries have promised to have more ambitious climate goals and 30 swore to be carbon neutral by midcentury, said Chilean President Sebastian Pinera Echenique, who is hosting the next climate negotiations later this year.

Heads of nations such as Finland and Germany promised to ban coal within a decade. Several also mentioned goals of climate neutrality - when a country is not adding more heat-trapping carbon to the air than is being removed by plants and perhaps technology - by 2050.

Before world leaders made their promises in three-minute speeches, 16-year-old climate activist Greta Thunberg gave an emotional appeal in which she chided the leaders with the repeated phrase, "How dare you."

"This is all wrong. I shouldn't be up here," said Thunberg, who began a lone protest outside the Swedish parliament more than a year ago that culminated in Friday's global climate strikes. "I should be back in school on the other side of the ocean. Yet you have come to us young people for hope. How dare you. You have stolen my dreams and my childhood with your empty words."

She told the U.N. that even the strictest emission cuts being talked about only gives the world a 50% chance of limiting future warming to another 0.4 degrees Celsius (0.72 degrees Fahrenheit) from now, which is a global goal. Those odds are not good enough, she said.

"We will not let you get away with this," Thunberg said. "Right now is where we draw the line."

Text of Greta Thunberg's speech:

"This is all wrong," Thunberg said. "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! How dare you.

"You have stolen my dreams and my childhood with your empty words, and yet, I am one of the lucky ones. People are suffering," Thunberg said. "People are dying. Entire ecosystems are collapsing. We are in the beginning of a mass extinction and all you can talk about is money and fairy tales of eternal economic growth. How dare you.

"For more than 30 years the science has been crystal-clear," Thunberg said. "How dare you continue to look away? And come here saying that you are doing enough when the politics and solutions needed are still nowhere in sight. You say you hear us and that you understand the urgency. But no matter how sad and angry I am, I do not want to believe that, because if you really understood the situation and still kept on failing to act, then you would be evil, and that I refuse to believe.

"The popular idea of cutting our emissions in half in 10 years only gives us a 50 percent chance of staying below 1.5 degrees and the risk of setting off irreversible chain reactions beyond human control," Thunberg said.

"Fifty percent may be acceptable to you, but those numbers do not include tipping points, most feedback loops, additional warming hidden by toxic air pollution, or the aspects of equity and climate justice. They also rely on my generation sucking hundreds of billions of tons of your CO2 out of the air with technologies that barely exist. So a 50 percent risk is simply not acceptable to us, we who have to live with the consequences," Thunberg said.

"To have a 67 percent chance of staying below a 1.5 degrees of global temperature rise, the best odds given by the IPCC, the world had 420 gigatons of CO2 left to emit back on January 1, 2018. Today that figure is already down to less than 350 gigatons.

"How dare you pretend that this can be solved with just business as usual and some technical solutions. With today's emissions levels, that remaining CO2 budget with be entirely gone within less than 8 and a half years," Thunberg said.

"There will not be any solutions or plans presented in line with these figures here today because these numbers are too uncomfortable and you are still not mature enough to tell it like it is," Thunberg said.

"You are failing us, but the young people are starting to understand your betrayal," Thunberg said. "The eyes of all future generations are upon you. And if you choose to fail us, I say we will never forgive you."