THEs the world economy wakes back up, shortages and price spikes are affecting everything from the supply of Taiwanese chips to the cost of a French breakfast. As we explain this week, one kind of bottleneck deserves special attention: the supply-side problems, such as scarce metals and land constraints, that threaten to slow the green-energy boom. Far from being transitory, these bottlenecks risk becoming a recurring feature of the world economy for years to come because the shift to a cleaner energy system is still only in its infancy. Governments must respond to these market signals, facilitating a huge private-sector investment boom over the next decade that increases capacity. If they don’t, they stand little chance of keeping their promises to reach “net-zero” emissions.