President-elect Joe Biden has said that one of the first acts of his presidency will be to return the United States to the Paris climate change agreement. His administration is proposing to make US electricity production carbon-free by 2035 and to have the country achieve 'net zero' emissions by the middle of the century. In 2015 the United States played a leading role in bringing together 195 countries that pledged to work together to keep the global temperature rise below two degrees Celsius. But less than six months after taking office Donald Trump said he’d withdraw from the agreement, claiming it was putting American jobs and the economy at risk. By the end of the Trump presidency the US had left - and had also rolled back dozens of environmental protections and implemented plans to expand drilling for oil and gas into public lands. So what has four years of President Trump done to global efforts to tackle climate change? How will America's return to the top table under a Democratic leader change the picture? Will President-elect Biden have the support he needs from Congress and the American people to meet his ambitious targets? And what now for US leadership in persuading other countries to commit fully to fighting climate change? Ritula Shah is joined by a panel of expert guests.