US President Donald Trump framed his sweeping rollback of federal climate change policy on Thursday as a political win over the Democratic Party's 'radical' environmental agenda, reprising a message Republicans have used in past elections and could turn to once again ahead of November's crucial midterms. His announcement at the White House was one of the most significant moves of his second term in office. The president said he was revoking an Obama-era 'endangerment finding' from 2009 which held that pollution harms public health and the environment.

For almost 17 years, the US has used that scientific finding as the legal basis to establish policies to reduce emissions from cars, power plants and other sources of planet-warming gases. 'This radical rule became the legal foundation for the Green New Scam,' Trump said, using a term popular with Republicans for describing Democratic environmental and climate policies. The move marks the culmination of a decade-long push by Trump to tear up policies that Democrats and many climate experts say are needed to rein in emissions. And it is one of the most far-reaching reversals of American climate policy yet.

Trump, who has called climate change a 'hoax' and a 'con job', dismissed the science underpinning the Obama-era rule in remarks that at times took on the air of a victory lap over his Democratic opponents. He focused on the economic impacts of reversing the endangerment finding, arguing that boosting fossil fuels instead of clean energy would lead to lower energy costs for American consumers.

Lee Zeldin, the administrator of the US Environmental Protection Agency, made the announcement alongside the president and described the 2009 scientific ruling as the 'holy grail of climate change religion'. Both Zeldin and Trump framed its revocation as an assault on overbearing federal regulations, part of a longtime message from Republicans that bureaucratic red tape is hindering economic growth.

This decision is 'the single largest act of deregulation in the history of the United States of America,' Zeldin said. The rollback sparked fury among Democrats and environmental groups who said it would wreck the US's ability to combat climate change. Trump reversed numerous Obama-era energy and environmental regulations in his first term in office, including the withdrawal from the Paris climate accord.

In recent years, climate policy in the US has swung wildly depending on who is occupying the White House, but Thursday's announcement represents the largest move yet by Trump to dismantle climate policies put in place by his Democratic predecessors. As Trump seeks to rally support for his administration, he faces an uphill battle: while some Republicans embrace his approach, opinion polls show growing concern among the public about climate change.