​Climate deal is positive - but now needs to be translated into action, say environmentalists.

Campaigners have warned that the real work starts now – after more than 150 nations formally signed the deal thrashed out at last year’s Paris climate summit.

While recognising the “historic” nature of the agreement, which was sealed on Earth Day (Friday, 22 April), environmentalists said governments now have to translate will into action.

Last December’s summit in the French capital saw the first ever international deal on curbing climate change being made.

It included a commitment to hold global temperature rises to less than 2°C above pre-industrial levels – with a goal of 1.5°C set.

The question is not just will we all act but will we act quick enough

Green groups welcomed the agreement – with major reservations over whether it goes far enough and how it will be implemented.

As the accord was signed at the United Nations HQ in New York, Tom Ballantine, chair of Stop CIimate Chaos Scotland, said: “The signing of the Paris agreement is an historic moment in the global fight against climate change. World leaders are reaffirming the commitments made in Paris and moving this agreement a step closer towards becoming international law.

“The agreement may not be perfect, but the commitment from the world’s biggest nations right to the smallest island states to take the action required and spur the clean development needed to tackle climate change is unparalleled.

“What matters now is how those leaders take those commitments to their own countries and back them up with low carbon action to reduce emissions. The question is not just will we all act but will we act quick enough.”

The agreement will need to be ratified into law in 55 countries, accounting for at least 55% of global greenhouse gas emissions, to come into legal force.