We hear US President Joe Biden's address to the UN's COP27 climate change summit in Egypt, as he outlines a plan to crackdown on methane leaks from the oil and gas industry. We hear from Daniel Kammen, a Professor of Nuclear Engineering at the University of California, Berkeley - and a climate change advisor to US administrations over two decades.

The major cryptocurrency exchange FTX has filed for bankruptcy protection in the United States. It caps a tumultuous week for the platform, which was worth billions of dollars just days ago. Alix Stewart, fund manager at the UK brokers Schroders, explains the significance.

Russian forces have retreated from the southern Ukrainian city of Kherson. Ukrainian forces have now regained control of that city, in a huge blow to Moscow. Meanwhile, western sanctions continue to hurt Russia, as the country's isolation from the west deepens. We hear from Sergey Aleksashenko, a former deputy minister of finance of the Russian Federation who also used to be a deputy governor of the Russian Central Bank.