China and the US have both announced they'll ratify a deal on climate change that was struck in Paris last year.

It means the world's two biggest polluters have agreed to cut emissions, ahead of a G20 summit being hosted by China this weekend.

President Obama - who arrived there this morning - hopes other nations will follow:

Green Party leader Eamon Ryan has welcomed the news, and he believes Europe needs to keep pace with global efforts to tackle climate change: