By Tuhin Sanzid 

Youth leaders gathered at the United Nations on Saturday to demand radical moves to fight climate change. At the first-ever Youth Climate Action Summit at the U.N. headquarters in New York on Saturday, 

Climate leader Greta Thunberg(15 years Swedish student) was joined by more than 600 young activists who were able to appeal directly to the U.N. secretary-general. 

“Young people from different parts of the world are living in constant fear and climate anxiety, fearing the future, the uncertainty of a healthy life or a life for their children at all,” young participants said.

Thunberg addressed the gathering briefly, noting that she will be speaking to world leaders at the larger U.N. Climate Action Summit on Monday.

Yesterday millions of people across the globe marched and demanded real climate action, especially young people, Thunberg said. We showed that we are united and that we young people are unstoppable.

Secretary-General Antonio Guterres thanked Thunberg and other young climate leaders from countries including Argentina, Kenya, and Fiji for helping to push for a prompt drawdown of fossil fuel emissions and investments by world governments in renewable energy.

The climate justice movement that Thunberg has helped to build in the past year has successfully convinced a number of national and local governments to declare a climate emergency and secured a commitment from the European Commission in February to dedicate a quarter of its spending to combating the climate crisis.

"You have started this movement," Guterres said. "I encourage you to keep your initiative, keep your mobilization, and more and more to hold my generation accountable." The secretary-general added that his generation has largely failed until now to preserve both justice in the world and to preserve the planet.

Some of the young advocates in attendance weren't convinced that Guterres's generation is much more committed to solving the climate crisis than it was before Thunberg captured the world's attention with the first climate strike—organized and attended solely by her in Sweden last year.

My generation has a huge responsibility – UN chief Guterres said that “one of the problems of world leaders [is that] they talk too much, and they listen too little. And … It is in listening that we learn. It is in giving the possibility for all those that represent today's world to speak and to have their voices be part of decision-making processes that we can move forward.”

While he painted a dire picture of the impacts of the climate emergency ­– from droughts in Africa to bleaching coral reefs and heatwaves elsewhere – the Secretary-General said he saw “a change in momentum” ahead of Monday’s Climate Action Summit, due to movements like those spearheaded by Ms. Thunberg, other grassroots activists and initiatives being undertaken “at the village level.” 

“I encourage you to go on To keep your mobilization and more and more to hold my generation accountable," “My generation has largely failed until now to preserve both justice in the world and to preserve the planet. My generation has a huge responsibility. It is your generation that must make us be accountable to make sure that we don't betray the future of humankind.” he added. 

The Climate Action Summit will kick off a series of high-level events at UN Headquarters on this week to drive action for people and the planet.