While teenagers serve as the public face of the lawsuit, the idea itself came from Julia Olson, an attorney based in Eugene, Oregon. Olson founded an organization called Our Children's Trust after watching the Al Gore documentary An Inconvenient Truth while she was seven months pregnant. Her idea to invite kids to become plaintiffs in a suit against the government was partly inspired by her colleague Mary Christina Wood, director of the Environmental and Natural Resources Law Program at the University of Oregon. Wood has spent her career studying the public trust doctrine, most recently devising a strategy she has dubbed Atmospheric Trust Litigation to apply that theory to the climate.

Wood told Olson about a case from the Philippines, where in the early 1990s a combative environmental attorney named Antonio Oposa represented 43 children, including some of his relatives, in a class action suit to defend the archipelago's small vestige of old-growth forest from logging firms. The children's case against the country's head of Environment & National Resources was ultimately upheld by the Philippines' Supreme Court, inspiring similar suits throughout the world.

Olson and other supporters of the suit believe that having kids as plaintiffs makes a particularly visceral appeal to adults to take action. Indeed, many of the adults involved said that their own children and grandchildren had inspired them. "Becoming a grandfather motivated me to speak out," said climate scientist James Hansen, the director of the U.S. NASA Goddard Space Institute and the man who first brought Loorz and Olson together. Hansen, in his free time, is a conscientious objector to U.S. energy policy who has been arrested three times at peaceful protests.

In support of the children's suit, Hansen has drawn up recommendations as to how the U.S. government can meet the greenhouse-gas reduction goals, through cuts in fossil-fuel-powered electricity and reforestation. "My talents are mainly in the sciences," he said, "but it just became so clear that no one is doing anything to prevent what is becoming scientifically a very clear picture. I didn't want my grandchildren to say that "Opa" (Dutch for "grandpa") knew what was happening but didn't do anything about it."

The tall, lanky Loorz is an especially compelling spokesman for the U.S. children's lawsuit. He became a climate activist at age 12, when, like Olson, spurred to action after watching An Inconvenient Truth -- in his case, twice in one evening. He went on to found an organization called Kids vs. Global Warming, and traveled the world, giving more than 200 speeches at schools and other venues to more than 100,000 people altogether.

The federal suit, which was first filed in California and then relocated to Washington, D.C., was initially coordinated with a dozen similar lawsuits against individual states. Four of those suits have been dismissed, while eight are still active, according to organization spokeswoman Meg Ward. With both the executive and legislative branches having been stymied on any major climate-change progress for more than two decades, the federal lawsuit represents a kind of Hail Mary pass, trusting that courts might bring about a speedier solution.