2021 - April 23rd United States President Joe Biden launches global climate summit by pledging to cut US emissions in half by 2030

 https://www.abc.net.au/news/2021-04-23/joe-biden-us-to-cut-emissions-by-half-by-2030/100089456

US President Joe Biden has pledged to slash US greenhouse gas emissions in half by 2030, amid an American-brokered Earth Day summit featuring leaders from 40 countries across the globe.

The United States, the world's second-leading emitter after China, seeks to reclaim global leadership in the fight against global warming after former president Donald Trump diminished US credibility in this policy area throughout his term. 

"This is the decade we must make decisions that will avoid the worst consequences of the climate crisis," Mr Biden said at the White House.

The IPCC, the UN's climate science panel, has calculated the global 2030 and 2050 emissions reduction targets need to give the world a "high likelihood" of keeping the Earth from warming to 1.5 degrees Celsius above pre-industrial levels by 2100. 

If temperatures rise between 1.5C and 2C of warming, the IPCC predicts that coral reefs will decline from 70-90 per cent to more than 99 per cent.

Sea level rise will displace a further 10 million people by the end of the century at 2C compared with 1.5C, and animal extinctions — as well as heat related mortality in people — will be far greater at 2C.