President Donald Trump said he would announce on Thursday his decision whether to keep the US in a global pact to fight climate change, as a source close to the matter said he was preparing to pull out of the Paris accord. This could have a domino effect on the participation of other countries in limiting fossil-fuel pollution. As a presidential candidate, Trump had said he would “cancel” the Paris pact and “focus on real environmental challenges, not the phony ones we’ve been looking at”. Trump has said the accord would cost the US economy trillions of dollars without tangible benefits.
If the US withdraws...
• The world would warm by 3.6 degrees Celsius by 2100 when compared with pre-industrial levels if Trump quits Paris, more than the 3.3-degree baseline scenario
• It would threaten a $100 billion-a-year stream of funds that industrial nations have pledged to persuade developing nations to cut back their own emissions
• So far, no other country, not even China or India has said they’d follow the US in pulling out of Paris. Instead, it’s catalysed support for the deal
• If the rest of the world followed Trump, it could add a total of 350 billion to 450 billion tonnes of carbon dioxide into the atmosphere
• The chances of meeting the UN target of staying well below 2 degrees of warming would drop to about 10 per cent, from two-thirds now
• China and the EU will seek on Friday to buttress the agreement. In a statement backed by all 28 EU states, the European Union and China will commit to full implementation of the accord, EU and Chinese officials said

Shift in the biggest polluters share in greenhouse gas emission
Can global warming be slowed without US involvement?
As the world’s second-biggest polluter, after China, the US has a key role to play in any attempt to tackle rising temperatures. The US also has agreed to contribute financially to help poorer nations invest in renewable energy. It had pledged to cut its carbon emissions 26-28 per cent from 2005 levels by 2025.