The major determinant of the experts’ estimates of the SCC was the climate
sensitivity (Table 1). Experts reporting generally low estimates (e.g., L1)
produced estimates exceeding £35/tC, but only for high climate scenarios and
usually with other decision factors. In the middle to high group of experts
(e.g., M1 and X2), values around £35/tC occurred for many climate scenarios,
and were quite common for middle to high scenarios. A decision tree of the
scenario responses found the importance of aversion to risk (from the range of
climate sensitivities), with intermediary contributions from the range of impacts
included (e.g., market and non-market, socially contingent), adaptation (as a
reduction in impacts), discount rate and decision perspective (e.g., global or
local).