What is grandfathering?

Emissions grandfathering maintains that prior emissions increase future emission entitlements. The view forms a large part of actual emission control frameworks, but is routinely dismissed by political theorists and applied philosophers as evidently unjust. A sympathetic theoretical reconsideration of grandfathering suggests that the most plausible version is moderate, allowing that other considerations should influence emission entitlements, and be justified on instrumental grounds. The most promising instrumental justification defends moderate grandfathering on the basis that one extra unit of emission entitlements from a baseline of zero emissions increases welfare to a greater extent where it is assigned to a high emitter than where it is assigned to a low emitter. Moderate grandfathering can be combined with basic needs and ability to pay considerations to provide an attractive approach to allocating emission entitlements