US President Barack Obama made a last pledge on the environment in his eighth and final State of the Union address on 13 January.
Obama has been a staunch advocate for the environment since taking office, placing an emphasis on climate change and the threat it poses to the future of the human race, and indeed the planet.
Environmental issues have been a historically unpopular topic in the US. Despite that, Obama entered presidential office in 2009 with the help of green pledges. In 2015 he also made a notable, emotional impression around the signing of the Paris Climate Agreement.
He has made various environmental achievements in the US during his presidency - including the finalisation of the Clean Energy Plan, blocking the Keystone XL pipeline plans, and banning Arctic drilling,
Perhaps most notably in his final State of the Union address, Obama gave thanks to much of the nation for helping in the push for a greener America, whilst unabashedly scorning climate change skeptics.
"Look, if anybody still wants to dispute the science around climate change, have at it," said Obama.
"You'll be pretty lonely, because you'll be debating our military, most of America's business leaders, the majority of the American people, almost the entire scientific community, and 200 nations around the world who agree it's a problem and intend to solve it.
"But even if the planet wasn't at stake; even if 2014 wasn't the warmest year on record?-?until 2015 turned out even hotter?-?why would we want to pass up the chance for American businesses to produce and sell the energy of the future?"
Obama's comments on the environment in his final State of the Union address could serve to pass the environmental torch between the current US administration and the next, depending on the state of Congress after the federal election.