Donald Trump has made good on his pledge to withdraw the US from the Paris Accord on climate change - an agreement aimed at tackling global warming.
Nearly 200 countries still remain committed to the deal signed in the French capital in 2015.
But where do the UK political parties stand on the environment and what are their policies heading into the election on June 8?
In its manifesto the Conservative Party pledges to produce a 25-year environment plan.
This would see the current generation become the first to "leave the environment in a better state than we inherited it", according to the manifesto.
A Tory government would fight against the degradation of habitat and loss of species, working with Overseas Territories to create a Blue Belt of marine protection.
At home, farmers would be offered technical expertise to deliver environmental improvements, while ancient woodlands would receive stronger protection.
Shale gas industries would be encouraged - under "rigorous" environmental standards - and planning laws relaxed to make fracking easier.
A greater percentage of taxes would go directly to the communities where shale gas wells are based.
Labour has promised that Britain would meet its climate change targets if it was in government.
The UK would also transition to a low-carbon economy, the party pledges.
Labour would "reclaim Britain's leading role in tackling climate change", working hard to preserve the Paris Accord and deliver on commitments to reduce emissions.
The manifesto promises to ban fracking, however.
Instead, it would reinvest in renewable energy projects, including tidal lagoons.
The party would seek to ensure EU environmental protections are maintained after Brexit and would champion sustainable farming, food and fishing.
Among Labour's other offerings are a new Clean Air Act, Blue Belt safeguards for habitats and species in the seas around the UK, targets for plastic bottle deposit schemes and a ban on neonicotinoids to protect bees.
The party would plant a million trees of native species across the country.
The Liberal Democrats also promise to maintain EU environmental standards in UK law after Brexit.
Tim Farron's party would also introduce five green laws. These include a Green Transport Act, a Zero-Carbon Britain Act, a Nature Act, a Green Buildings Act, and a Zero-Waste Act.
Among its environmental pledges, the Lib Dems would insulate four million properties, cut deaths from air pollution by 40,000 a year and refocus farming support towards producing healthy foods and public benefits.
New diesel cars and small vans would be banned, while the party would also extend ultra-low emission zones to 10 more towns and cities.
A tree for every UK citizen would be planted and a 5p charge levied on disposable coffee cups.
The party aims to generate 60% of electricity from renewables by 2030.
Scottish National Party
Similarly to the Liberal Democrats, the SNP insists that EU environmental rights and protections will not diminish after Brexit.
The party argues that environmental powers repatriated from Brussels should go to Holyrood, not Westminster.
Low cost renewable energy and Scotland's renewables industry will also be championed.
This includes an onshore wind strategy and supporting renewable energy projects in the Northern and Western Isles
The SNP aims to make Scotland a world leader in Carbon Capture and Storage.
Its MPs will press Westminster to follow the "commitment and ambition" shown in the Scottish Government's draft Climate Change Plan.
The Green Party promises to put the environment "at the heart of everything" it does.
It pledges to introduce an Environmental Protection Act aimed at enhancing biodiversity, promoting sustainable food and farming, and ensuring animal protection.
Insulation of homes will be pursued and flood defences invested in.
The party aims to limit global temperature increases to well below 2C, hoping for 1.5C.
Fracking, coal power stations, subsidies to fossil fuels and nuclear energy will be replaced with clean green efficient renewable energy.
A one-off fine on car manufacturers who cheated the emissions testing regime would be handed down, while the party would introduce a new Clean Air Act.