President Donald Trump speaks between Vice President Mike Pence, left, and EPA Administrator Scott Pruitt prior to signing an executive order on "Energy Independence", eliminating Obama-era climate change regulations, during an event at the Environmental Protection Agency (EPA) headquarters in Washington, U.S., March 28, 2017.
The decree, dubbed the "Energy Independence" order, will seek to undo former President Barack Obama's Clean Power Plan requiring states to slash carbon emissions from power plants - a critical element in helping the United States meet its commitments to a global climate change accord agreed by almost 200 countries in Paris in December 2015.
Some experts and environmental groups also warned that Trump's order could be the opening salvo of an effort to undermine internationally agreed targets under the Paris Climate Accord, which was reached by almost 200 countries in 2015.
Following yesterday's EO allows the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Justice (DOJ) asked the Court of Appeals for the D.C. Circuit to seek a freeze of current litigation over these rules while the EPA decides whether and how to revise or rescind the Clean Power Plan. It also calls for a new analysis of the social cost of carbon which was fundamental to the cost-benefit analysis of climate change regulations including the Clean Power Plan.
It is a key factor in the U.S.'s ability to meet its commitments under the United Nations climate change agreement reached by almost 200 countries in Paris in 2015.
But, President Trump's executive order targets those environmentally friendly policies.
They certainly thought through what they were and were not going to include, said Ann Weeks, legal director at the nonprofit Clean Air Task Force, which plans to oppose Trump administration efforts to suspend the power plant court cases.
But with its capital often choked by smog and its people angry about the environmental devastation that rapid development has wrought across the country, Beijing has become a strong proponent of efforts to halt global warming rather than a hindrance. It requests an end to an existing moratorium of new coal mines on federal land, and rolls back pollution rules that affect the oil and gas industry.
Trump did not say whether he would pull out of the Paris Agreement, a pact agreed to by nearly 200 nations that seeks a shift from fossil fuels this century as the cornerstone of efforts to limit heat waves, floods, droughts and rising sea levels.
The historic worldwide climate deal has been a top target of Trump, who appears hell-bent on dismantling his predecessor's legacy.
Under the Paris Agreement, the US has promised to reduce its carbon emissions 26 to 28 percent below levels recorded in 2005.
Environmental activists criticized the executive order, arguing it takes the U.S.in the wrong direction.
But Tillerson himself is credited with steering ExxonMobil towards public acceptance of the science of climate change.
The Administration has a tough road ahead in carrying out the President's order.