Extensions and alternatives to climate change impact valuation: On the critique of IPCC Working Group III's impact estimates

The paper discusses valuation issues in the context of climate change impact estimation. Issues addressed are aggregation of damage costs over diverse regions (particularly equity-weighting), differentiation of per-unit values, willingness to pay versus willingness to accept compensation as a basis for valuation, and accountability for impacts. Numerical illustrations show that the damage cost estimates are quite sensitive to the assumptions made on these issues.