1. ITV Report

US and China ratify Paris agreement on climate change ahead of G20

The United States has joined China in formally ratifying the Paris agreement on climate change, which could see the deal brought into force before the end of the year.

Video report by ITV News China correspondent Debi Edward reports:

The announcement - which has prompted calls for the UK to follow suit - came as leaders from the world's biggest economies, the G20, started to arrive in Hangzhou for a summit on Sunday and Monday.

US President Barack Obama and Chinese President Xi Jinping submitted their plan to join the agreement to UN Secretary-General Ban Ki-moon, who travelled to China to witness the announcement.

Barack Obama has joined other world leaders at the G20 Summit in Hangzhou. Credit: Reuters

The standing committee of China's parliament earlier voted to adopt the "proposal to review and ratify the Paris Agreement" at the closing meeting of a week-long session.

Obama and Xi committed to cooperate on two other global environmental agreements this year.

The first is an amendment to the Montreal Protocol related to air-conditioning in refrigeration and the second aimed to reduce carbon emissions from flying.

Why G20 action is vital in climate change battle

China is the world's biggest polluter. Credit: Reuters

G20 nations are responsible for around 80% of global carbon emissions, with China being the largest, and the US the second largest emitter.

Nearly 200 countries agreed in Paris last December to slash greenhouse emissions and keep global temperature increases "well below" 2C.

While 180 countries have signed the agreement, some 55 nations - who are responsible for at least 55% of global emissions - need to formally ratify the treaty to put it into legal effect.

Praise for US and China

Xi Zinping welcomed leaders to the G20 summit in Hangzhou. Credit: APTN

The combined weight of the world's two biggest economies behind the Paris Agreement earned the nations praise from the UN's climate chief.

I would like today to thank China and the United States for ratifying this landmark agreement - an agreement on which rests the opportunity for a sustainable future for every nation and every person. The earlier that Paris is ratified and implemented in full, the more secure that future will become.

– United Nations climate chief Patricia Espinosa

Campaigners urge the UK to follow suit

There have been calls for countries to ratify the Paris deal as soon as possible, so it can be adopted earlier than the planned 2020 start date, to meet the urgent need to tackle climate change.

Campaigners have urged the UK to follow suit.

There are no excuses left for the UK Government to delay the ratification of the Paris deal, least of all Brexit. If anything, the UK has never been more in need to demonstrate it's a reliable partner on its international commitments.

– Greenpeace UK chief scientist Dr Doug Parr

On Wednesday there will be a debate in the House of Commons at which the UK Government will have a chance to set out their timeline for ratification. If the UK intends to retain its climate leadership on the global stage it mustn't show up late to the party.

– Mohamed Adow, Christian Aid's senior climate advisor

The new Prime Minister must continue British leadership on climate change. By quickly ratifying the Paris Agreement, and pushing for a strong global deal to limit aircraft emissions at the International Civil Aviation Organisation conference this month, the Government could show the world that the referendum vote hasn't watered down any resolve to deliver a low-carbon word and meet our global commitments.

– WWF-UK's head of climate and energy Emma Pinchbeck