Assessing the Costs of Adapting to Climate Change

The review of previous studies by the International Institute for Environment and Development dated August 2009 concludes that this re-assessment of the UNFCCC estimates for 2030 suggests that they are likely to be substantial under-estimates. The purpose of this report is to illustrate the uncertainties in these estimates rather than to develop new cost estimates, which is a much larger task than can be accomplished here.

The main reasons for under-estimation are that: (i) some sectors have not been included in an assessment of cost;
(ii) some of those sectors which have been included have been only partially covered; and
(iii) the additional costs of adaptation have sometimes been calculated as ‘climate mark-ups’ against low levels of assumed investment.

Residual damages also need to be evaluated and reported because not all damages can be avoided due to technical and economic constraints.