Glencore plc is an Anglo-Swiss multinational commodity trading and mining company with headquarters in Baar, Switzerland, its oil and gas head office in London and its registered office in Saint Helier, Jersey. The current company was created through a merger of Glencore with Xstrata on 2 May 2013. As of 2015, it ranked tenth in the Fortune Global 500 list of the world's largest companies. In the 2020 Forbes Global 2000, Glencore International was ranked as the 484th-largest public company in the world.As Glencore International, the company was already one of the world's leading integrated producers and marketers of commodities. It was the largest company in Switzerland and the world's largest commodities trading company, with a 2010 global market share of 60% in internationally tradable zinc, 50% in internationally tradable copper, 9% in the internationally tradable grain market and 3% in the internationally tradable oil market.Glencore had a number of production facilities all around the world and supplied metals, minerals, crude oil, oil products, coal, natural gas and agricultural products to international customers in the automotive, power generation, steel production and food processing industries. The company was formed in 1994 by a management buyout of Marc Rich + Co AG (itself founded in 1974). It was listed on the London Stock Exchange in May 2011 and was a constituent of the FTSE 100 Index. It had a secondary listing on the Hong Kong Stock Exchange, but it has withdrawn from January 2018. Glencore's shares started trading on the Johannesburg Stock Exchange in November 2013. The Qatar Investment Authority is its biggest shareholder.Glencore is responsible for 0.38% of global industrial greenhouse gas emissions from 1988 to 2015 and thus one of the largest contributors to climate change, which bears substantial “risks to health, livelihoods, food security, water supply, human security, and economic growth”.