The global economy is facing twin shocks. Natural resource markets are delivering a supply shock of 1970s dimensions, while the financial system is delivering a shock comparable to the bank and thrift crises of the 1988-1993 period. The magnitude of each shock is very different. The financial markets require a recapitalisation of the banking system, with estimates ranging from $300bn to $1,000bn.

By contrast, prospective capital requirements in the resource markets dwarf the current needs of the banking system. According to the International Energy Agency, the global energy sector alone needs a real $22,000bn over the next two decades to meet the anticipated rise in primary energy demand. There is also the unavoidable necessity to reduce the CO2 intensity of energy production, a good 80 per cent of which is derived from the dirtiest of fossil fuels. While an accurate quantification of the size of the required green energy investment is not possible, it is likely to be of a similar scale to the expansion of energy supply.