London (AFP) – Britain ratified the Paris agreement on climate change Thursday, joining more than 100 other countries in a move that campaigners hope will prompt US President-elect Donald Trump to honour the deal.

Foreign Secretary Boris Johnson signed the Paris Agreement as countries met in Morocco for the latest round of United Nations climate talks, focused on implementing the treaty by the end of the year.

“The Paris Agreement has completed the 21 day sitting period before parliament and the Instrument of Ratification has been signed by the Foreign Secretary,” the foreign ministry said in statement.

The pact commits countries to limiting global temperature rises to “well below” 2 degrees Celsius over pre-industrial levels and pursue efforts to keep increases to 1.5 degrees Celsius.

The move was hailed by environmental campaigners.

“It has never been more important for the world to stand together on climate change and the UK joining the Paris Agreement is a welcome signal,” said Stephen Cornelius, chief adviser on climate at WWF-UK.

ClientEarth said: “The UK’s ratification of the Paris Agreement is a welcome sign that the world is forging ahead with climate action.

“President-elect Trump should take this ratification, and the comments by China, France and others in recent days as a warning that any reneging on the agreement would make the US a global environmental pariah,” the group said in a statement.

Trump’s election victory this month has shocked UN diplomats and notably put a question mark over the fate of the Paris climate deal championed by UN chief Ban Ki-moon during his 10 years at the helm.

Speaking at the UN climate conference in Marrakesh, US Secretary of State John Kerry underlined the perils that await the world if leaders drag their feet on cutting planet-warming greenhouse gases.

“At some point even the strongest sceptic has to acknowledge that something disturbing is happening,” Kerry told delegates on Wednesday.

Before his election, Trump called climate change a “hoax” perpetrated by China and vowed to “cancel” the hard-fought Paris Agreement concluded last year to limit dangerous global warming.

China and the United States, the two largest emitters, gave a major boost to the accord when they signed on during a summit in September between Presidents Xi Jinping and Barack Obama.