Figure — The modeled relationship between carbon taxes in 2050 (a proxy for general climate policy controls) and the probability of DAI in 2100. Each color band represents a different percentile range from the DAI threshold CDF—a lower percentile from the CDF representing a lower temperature threshold for DAI, as indicated. The solid lines indicate the percentage of outcomes exceeding the stated threshold for DAI[X‰], where X is the percentile from the DAI CDF derivable from the adaptation of the IPCC Reasons for Concern figure, for any given level of climate policy controls. At any DAI[X‰] threshold, climate policy controls significantly reduce the probability of DAI, and at the median DAI[50‰] threshold (thicker black line), a 2050 carbon tax of $150/ton of C is the model-dependent result necessary to reduce the probability of DAI from 45% to near zero. [With a 3% PRTP, this carbon tax is an order of magnitude less and the reduction in DAI is on the order of 10%]. (Source: Mastrandrea and Schneider, 2004.)