As national leaders meet to thrash out what they are prepared to do to promote the growth of renewable energy ahead of fossil fuels, the reality is they have largely decided market forces will be used for delivery. Governments have been reining in the subsidies that have been used to encourage investment in renewables such as wind and solar as their operational costs begin to approach those of existing fossil fuels.

The good news for renewables is that subsidies for the competition look to be on the way down as well. Even excluding the externalities – the environmental costs – of fossil fuels that are rarely included in calculations, direct government subsidies to fossil fuels have long outweighed any others. A recent report compiled by the International Renewable Energy Agency (IRENA) estimated more than two-thirds of the $634bn (£458bn) spent on energy subsidies went into fossil fuels in 2017.

A quarter of the total energy subsidies worldwide were used...