US President Donald Trump on Tuesday signed an executive order rolling back Obama-era rules aimed at tackling global warming.

The order seeks to suspend, rescind or flag for review more than a half-dozen measures in an effort to boost domestic energy production in the form of fossil fuels.
As part of the roll-back, Trump will initiate a review of the Clean Power Plan, which restricts greenhouse gas emissions at coal-fired power plants. The regulation, which was the former president's signature effort to curb carbon emissions, has been the subject of long-running legal challenges by Republican-led states and those who profit from burning oil, coal and gas.
The President signed the order at the headquarters of the Environmental Protection Agency, saying that this is "the start of a new era" in energy production. He also said that his administration was going to "end the war on coal".
Trump has previously called global warming a "hoax", and has repeatedly criticised ex-President Barack Obama's efforts as an attack on American workers and the struggling US coal industry.

Environmental advocates were not surprised by the order - given such remarks - but said Trump has not considered the public health and economic implications of not fighting climate change or how the order negatively affects US standing in the world.
Laurence Tubbiana, formerly the top French diplomat on climate change and now the CEO of the European Climate Foundation, said in a statement that the order "will propel the economy backwards".
Anne Kelly a Senior Director at Ceres, a coalition of investors and business that promote sustainability, told the Independent that the Clean Power Plan was the "crown jewel of the Obama administration's climate plan".
Trump gave his statement after an off-camera signing ceremony, flanked by coal miners from West Virginia.
He said the order would "start a new era…[in] making America wealthy again".
Given that private sector investment in the renewable energy industry hit $350 billion in 2016 globally, outpacing new investment in the oil and gas sector for the first time, Kelly said she expects the "marketplace is going to go forward regardless of what the White House does".
Several of the country's largest pension funds, accounting for tens of billions in investment, have already begun divesting money from oil and gas companies in order to ensure a more profitable future for their investors.
However, they do require the EPA to do its part in the regulatory realm.
In 2007, under Republican George W. Bush's administration, the Supreme Court ruled that carbon emissions were essentially a pollutant, Ms Kelly explained.
The ruling made it the EPA's responsibility to regulate carbon pollution as a matter of public health after a series of "endangerment hearings." Kelly said states were given quite a bit of flexibility in how to reach the goal of reducing carbon emissions as well.
Trump also said during his speech that safety, clean water, and clean air are still priorities, but that his latest order will eliminate the "crushing attack" on economic freedoms, jobs in coal mining, and American manufacturing by the "bad" regulations.