Xiuhtezcatl Tonatiuh, 15, is suing President Obama over climate change. Tonatiuh was the recipient of the United States Community Service Award in 2013 which was presented by President Obama for his environmental activism. Now, the teenager from Colorado is joining forces with climate scientist James Hansen to sue the Obama administration for a lack of action in forgoing fossil fuels.

Tonatiuh was one of the young activists present at the 2015 United Nations Climate Change Conference, COP21, taking place in Paris today. The summit includes a number of world leaders who are in attendance including President Barack Obama, French President Francois Hollande and Chinese President Xi Jinping.

Tonatiuh spoke with CNN’s John Sutter at COP21 about the lawsuit filed by 21 young activists and scientist James Hansen against the Obama administration. He said:

“It’s basically a bunch of kids saying you’re not doing your job.

“You’re failing, you know. F-minus. We’re holding you accountable for your lack of action.”

Tonatiuh, who became a climate change activist after watching an environmental documentary at the age of six, says he is a part of the “generation with the most to lose.” Though it is uncertain what kind of ramifications there will be for the lawsuit, the fossil fuel industry appears to be threatened and have attempted to have the legal action dismissed.

Tonatiuh’s voice won’t be easily brushed aside as the urgency of his message can clearly be felt at the summit, which is hosting over 140 world leaders and thousands of advocates and reporters. He even launched his own website called Earth Guardians to spread his message and encourage others to take part in the cause.

The teenager acknowledges that Obama has made past attempts to address the climate issue, but it is not enough. Tonatiuh recalled Obama’s words:

“[Obama] said it before, that climate change is one of the most pressing issues of our time. That in his lifetime, he wants to see the slowing of rising seas. We’ve all seen that speech. Talk is cheap. I wanna see concrete action and concrete promises from our country — and commitments for action on climate change.”

“The reason we are fighting for this is because of the world we want to grow up in, and the world we want our children and grandchildren and great-grandchildren to grow up in. This is not a selfish cause. We’re not politically invested, we’re not financially invested. … We are in this because of the way it affects the state of the planet we want to be left with. That is the most noble cause I’d say: Leaving our children a better planet than the one we are living in today. We are doing our part. We need political leaders to step up and do theirs.”