Short answers, pulled from the story.
The formal establishment of the Group of 20 occurred on the 26th of September 1999 during a meeting of G7 Finance Ministers in Berlin. Hans Eichel, the German Finance Minister, hosted the inaugural gathering on the 15th and the 16th of December 1999. This event brought together finance ministers and central bank governors from nineteen countries and the European Union.
Paul Martin, the Canadian Finance Minister, and Larry Summers, the United States Treasury Secretary, created the G20 in response to the collapse of Long-Term Capital Management in the autumn of 1998. They realized the G7 was insufficient to maintain order in a rapidly globalizing economy and drafted a blueprint to include emerging markets as equal partners. Their vision was to create a permanent forum where the largest economies could coordinate policy without the constraints of the old Bretton Woods system.
The G20 adopted a system of rotating presidency where a different member country assumes the chair for a year from the 1st of December until the 30th of November. This system has been in place since 2010 when South Korea held the G20 chair. The presidency is supported by a troika consisting of the current, immediate past, and next host countries to ensure a smooth transition of secretariat functions.
Indian Prime Minister Narendra Modi announced the inclusion of the African Union as a member of the G20 in September 2023 at the 18th G20 Summit in New Delhi. The African Union was officially represented at the 2024 summit in Rio de Janeiro, Brazil. This inclusion marked the first expansion of the group since 1999 and made the African Union the 21st member.
G20 members subsidized fossil fuel companies over $3.3 trillion between 2015 and 2021 despite accounting for almost 75% of global carbon emissions. Several states increased subsidies including Australia, the US, Indonesia, France, China, Brazil, and Mexico. China alone generates over half of the coal-generated electricity in the world.
The 2010 Toronto G20 summit sparked mass protests and rioting that led to the largest mass arrest in Canada's history. The event highlighted the cost and extent of summit-related security which have often been a contentious issue. The group has been a target for anti-globalization groups who see it as a symbol of corporate power and inequality.