"This action will only lead to more of this pollution, and that will lead to higher costs and real harms for American families," Fred Krupp, president of Environmental Defense Fund, said in a statement.

NEW YORK, Feb. 13 (Xinhua) -- The Trump administration's move to revoke a key 2009 climate determination has sparked widespread criticism and legal challenges.

The determination underpins rules governing greenhouse gas emissions from motor vehicles, as well as policies promoting electric vehicle adoption.

Known as the 2009 Greenhouse Gas Endangerment Finding, the determination concluded that carbon dioxide, methane and four other greenhouse gases endanger public health and welfare. That conclusion has since served as the statutory basis for measures such as vehicle emissions standards and mandatory emissions reporting by fossil fuel companies.

"We are officially terminating the so-called endangerment finding, a disastrous Obama-era policy that severely damaged the American auto industry and drove up prices for American consumers," U.S. President Donald Trump said at a news conference on Thursday.

The move is expected to face legal challenges and could reach the Supreme Court, which in 2007 ruled that greenhouse gases qualify as pollutants under the Clean Air Act. The U.S. Environmental Protection Agency (EPA) now says the Clean Air Act "does not provide statutory authority" for the agency to set greenhouse gas emission standards for vehicles.

The repeal comes as the past three years have been the hottest on record globally. Last month, the United States formally withdrew from the 2015 Paris Agreement for a second time and is also expected to exit the United Nations Framework Convention on Climate Change, the main UN treaty governing global climate negotiations.

Former U.S. President Barack Obama, whose administration established the endangerment finding, criticized the decision in a statement. "Without it, we'll be less safe, less healthy and less able to fight climate change -- all so the fossil fuel industry can make even more money," he said.

Environmental groups expressed opposition to the move and said they are considering legal challenges.

The Endangerment Finding is not a political statement but a scientific conclusion, grounded in decades of evidence, said Lisa Patel, a pediatrician and executive director of the Medical Society Consortium on Climate and Health.

"This is not a neutral administrative action. It is a decision that will shape the clinical realities we confront for years to come by tearing back climate regulations and making it harder for future administrations to impose new ones," said Patel in a piece on Thursday.

"Removing EPA's authority to limit deadly greenhouse gas emissions is as shortsighted as it is reckless. Communities will suffer as extreme weather continues to threaten us all, costs will continue to rise, and we will saddle future generations with a world that grows increasingly unlivable and endangers the life we know," Loren Blackford, acting executive director of Sierra Club, an environmental organization, said in a statement released on Wednesday.

"This action will only lead to more of this pollution, and that will lead to higher costs and real harms for American families," Fred Krupp, president of Environmental Defense Fund, said in a statement released Tuesday, announcing the agency will challenge the decision in court.

The American Lung Association, the American Public Health Association, the Alliance for Nurses for Healthy Environments and Physicians for Social Responsibility also announced plans to challenge the "unlawful repeal" in a joint statement.

"This is a dark day for science and health. Climate change harms health -- period. By refusing to acknowledge and act on this, America's health will suffer preventable harm," said Harold Wimmer, president and CEO of the American Lung Association.

Overturning the Endangerment Finding and eliminating cleaner vehicles rules will result in more air pollution, more frequent and intense disasters like wildfires and floods, and increased risk of diseases, making lung health worse across the United States, warned Wimmer.

The future of the repeal could ultimately rely on the U.S. Supreme Court, according to Michael Gerrard, founder of the Sabin Center for Climate Change Law at Columbia University.