Xiuhtezcatl Tonatiuh is a 15-year-old environmental activist from Boulder, Colorado, who has spent his entire life fighting against climate change.Along with 20 other young environmentalists, Tonatiuh is suing the US government in a federal lawsuit, arguing that his generation's rights are being violated by the national failure to do anything about climate change.In this video, VICE heads to Tonatiuh's home in Boulder to find out how he became a leading voice for the generation likely to be most affected by climate change, and travels with him to Eugene, Oregon, for the federal hearing that determined whether their suit could go forward.