Why reduce the question to economics? A significant reason why developing countries continue to rely on coal power, for example, is political: energy insecurity, state tariffs, vested interests. At the same time they expect the global North, that is responsible for the greatest share of historic emissions, and has reaped its rewards, to help them. The North's failure to do so is a political issue, not a merely economic one. We will not reach net zero by 2050 without major state investment, regulation and international cooperation.