US President Donald Trump set out to obliterate his predecessor Barack Obama's legacy on climate change as part of a bid to unleash America's energy potential.

Mr Trump last night signed a sweeping executive order slashing measures from the Obama era, a move that was welcomed by the oil and coal industries as a bold step to end regulations that were "choking" the economy.

Environmentalists condemned the move, accusing Mr Trump of wanting to "travel back to when smokestacks damaged our health" and said they would take his administration to court.