Lord Browne is co-head of Riverstone Holdings, the world’s largest renewable energy fund, with $3.5 billion (£2.2 billion) in equity. It specialises in energy investments, and is best-known as the main backer, with a 44% holding, of Cuadrilla, the UK’s most prominent fracking company. Its oil exploration activities in the West Sussex village of Balcombe have met with high-profile protests.