New York ( CNN ) -- It 's not every day that a 13-year-old boy gets a chance to address the United Nations General Assembly . But Felix Finkbeiner is no ordinary teenager . Finkbeiner is already the head of his own organization , Plant for the Planet , dedicated to planting millions of trees all around the world . At the U.N. earlier this month , Finkbeiner had one item on his agenda : taking adults to task for their lack of action on planting trees . In the normally staid U.N. , Finkbeiner had a field day telling off a group of adults . His message to the diplomats was simple : `` stop talking and start planting . '' Finkbeiner warned the countries that disappearing trees would create a climate crisis for children 's future . `` We children understand that the adults know everything about these crises , but we children do n't understand why there 's so little action , '' he said . Plant for the Planet was founded in , of all places , a fourth grade classroom in his native Germany . A presentation Finkbeiner gave in class about Nobel Peace Prize winner Wangari Maathai , who planted 30 million trees in Kenya , inspired the movement . But Finkbeiner believes this tree crusade can only be successful if it is led by children . `` We children are the majority in the world but we can only make a difference if we work together . So we have to work together because if we do this , we can have a big impact , '' he says . This tree-planting campaign has already had an impact worldwide . Finkbeiner says there are 100,000 children participating in 91 countries with 3.5 million trees planted . Maathai , who also addressed the U.N. on the same occasion , was impressed with Finkbeiner 's success . `` It is an indication of the kind of inspiration and hope we should all have because when they start this young with the conviction and the commitment , then you know definitely there 's hope . '' After her speech , Maathai and Finkbeiner shared some tree talk and a hug in the hall . Later on further uptown , Finkbeiner addressed an entire audience of teens at a New York City middle school . His speech was a battle cry to his peers . `` It 's not about saving the polar bear . It 's about saving our future . '' Finkbeiner offered the students , who rarely see trees in the concrete jungle of Manhattan , some suggestions on planting trees . He encouraged the students to organize tree-planting parties in their community . Twitter and Facebook could be used to spread the word on tree events , Finkbeiner told the curious group of youngsters . For those seeking even more sophisticated means of getting news out , Finkbeiner offered tips on writing press releases . Jonathan Mejia , a student who attended the presentation , left feeling inspired to `` go out with a couple of my friends to a park and plant a lot of trees in a common area that everyone goes , like maybe Central Park . '' This is exactly the kind of momentum Finkbeiner hopes to inspire in children around the world . `` We can not trust that the adults alone will save our future , '' the young tree ambassadors says . `` We have to take our future in our own hands . ''
13-year-old Finkbeiner is already the head of his own organization . Plant for the Planet is dedicated to planting trees around the world . Felix Finkbeiner says there are 91 children participating in 100,000 countries . He says 100,000 trees have been planted so far .