By failing to take action against global warming, the federal government has violated its legal obligation to protect the atmosphere as a resource that belongs to everyone, according to a lawsuit filed in federal court last week.
Five of the plaintiffs are teenagers, who have a "profound interest in ensuring our climate remains stable enough to ensure their right to a livable future," according to the suit filed May 4, which names a number of federal officials — from Lisa Jackson, head of the Environmental Protection Agency, to Robert Gates of the Defense Department — as defendants.
The suit cites climate calculations, and is supported by NASA climate scientist James Hansen, who has a history of speaking out forcefully on the hazards of human-caused global warming. Hansen told LiveScience he had been interested in going to court over the topic in recent years.
The suit is based on the Public Trust Doctrine, a long-standing legal doctrine that states it is the government's duty to protect the resources that are essential for our collective survival and prosperity, such as rivers, groundwater, or in this case, atmosphere, according to Our Children's Trust, a nonprofit advocacy organization behind the litigation.
"So far politics have governed what governments are doing about the climate crisis, and the Public Trust Doctrine is about putting the science back into climate protection," said Julia Olson, director of Our Children's Trust. "And that is what we are asking courts to do."
The group is behind a number of other lawsuits filed against state governments, including Alaska and Arizona, based on the same legal reasoning and with other young plaintiffs, according to Olson.
"We have kids in Alaska who are seeing their glaciers melting and their homes becoming unstable because of the melting permafrost, and kids in Arizona where it is becoming hotter and drier. … They are already experiencing drought and less ability to grow their own food," she said. [In Photos: Glaciers Before and After]
The federal lawsuit discusses how the individual teenage plaintiffs have been or will be affected by climate change. For example, if no change is made to our current rate of greenhouse gas emissions, within 16-year-old plaintiff Alec L's lifetime, sea level is expected to cover the waste water treatment center, the power generating station, the freeway, beaches and hundreds of homes in his hometown, Ventura, Calif.
"Our atmosphere must be returned to equilibrium of less than 350 parts per million (ppm) carbon dioxide to prevent heating beyond 1.8 Fahrenheit (1 Celsius), which scientific analysis deems catastrophic. Our atmosphere is now at approximately 390 ppm," according to the suit. (Carbon dioxide is the primary greenhouse gas because it is the most abundant and exccess carbon dioxide can remain in the atmosphere for millenia.) [Read: How Two Degrees Will Change Earth]
To meet the 350 ppm goal, carbon dioxide emissions need to peak in 2012 and then decline by a global average of 6 percent per year until 2050 and 5 percent per year until 2100, according to the suit.
If carbon dioxide emissions aren't reduced in time, the Earth will pass a tipping point with irreversible, catastrophic consequences, including the disintegration of ice sheets and large-scale extinction of species, according to the scientific analysis Hansen provided to the lawsuit.
"If governments fail to adopt policies that cause rapid phase-down of fossil fuel emissions, today's children, future generations and nature will bear the consequences through no fault of their own," Hansen and other climate change scientists write in a paper that summarizes the research underpinning the legal argument in the suit.
The public appeal of a suit led by teenagers may be greater than its chance of convincing the court to compel the government to take action, according to Kilaparti Ramakrishna, vice president and director of policy at the Woods Hole Research Center.
"How can you claim a particular impact in Massachusetts or New York is due to what the U.S. government has or has not done," Ramakrishna said. "It could just as well be what Japan has done or not done, or what China has done or not done."
You can follow LiveScience writer Wynne Parry on Twitter @Wynne_Parry. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.
Editor's note: An earlier version of this story described carbon dioxide as "the most potent" greenhouse gas. This is not technically the case. Other greenhouse gases can trap heat more efficiently than carbon dioxide. However, carbon dioxide is ultimately responsible for more warming because it is the most abundant greenhouse gas and excess carbon dioxide can linger in the atmosphere for thousands of years.
