counting, risk aversion and ambiguity aversion. The study also included the development of
a multi-agent model of the Sahel.
3Note the values cited are mostly in the year of the study, i.e. they are not increased to
consistent year 2000 or year 2005 prices.
4The author, Richard Tol, concludes that ‘using standard assumptions about discounting
and aggregation, the marginal damage costs of carbon dioxide emissions are unlikely to exceed
$50/tC, and are probably much smaller’
5It should be noted that such trends may change in future analysis. Two recent findings are
that climate sensitivity and the likelihood that severe impacts increases at lower temperature
changes may be higher than previously expected (Schellnhuber & et al., 2005).