President Barack Obama is at the U.N. COP21 climate change summit in Paris facing a lawsuit from a 15-year-old environmentalist. Xiuhtezcatl Tonatiuh is suing Obama for failing to act on climate change. Tonatiuh is one of 21 plaintiffs suing the president for his failure to stop the United States from using fossil fuels.

The Colorado teenager hopes the lawsuit sends a message to Obama. "It's basically a bunch of kids saying you're not doing your job," said Tonatiuh, according to CNN. "You're failing, you know. F-minus. We're holding you accountable for your lack of action."

While the lawsuit may seem frivolous, oil companies are apparently threatened by the lawsuit since they are trying to get it dismissed.

"Seeing giant fossil fuel corporations inject themselves into this case, which is about our future, really demonstrates the problem we are trying to fix," Tonatiuh said, according to the environmental group Our Children's Trust. "The Federal government has been making decisions in the best interest of multinational corporations and their profits, but not in the best interest of my generation and those to come."

Obama acknowledged during the Paris conference that the U.S. has to act on climate change and reduce carbon emissions.

"I've come here personally, as the leader of the world's largest economy and the second-largest emitter, to say that the United States of America not only recognizes our role in creating this problem, we embrace our responsibility to do something about it," said Obama, according to the New York Times.

Tonatiuh, who is also attending the climate change conference, said Obama's words aren't enough. "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," said Tonatiuh, according to CNN.