Assessing the costs of adaptation to climate change: A review of the UNFCCC and other recent estimates
Several recent studies have reported adaptation costs for climate change, including for developing
countries. They have similar-sized estimates and have been influential in discussions on this issue.
However, the studies have a number of deficiencies which need to be transparent and addressed
more systematically in the future. A 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 (e.g. ecosystems, energy, manufacturing,
retailing, and tourism); (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. In some parts of the world low levels
of investment have led to a current adaptation deficit, and this deficit will need to be made good
by full funding of development, without which the funding for adaptation will be insufficient.
Residual damages also need to be evaluated and reported because not all damages can be avoided
due to technical and economic constraints. There is an urgent need for more detailed assessments
of these costs, including case studies of costs of adaptation in specific places and sectors.
Martin Parry, Nigel Arnell, Pam Berry, David Dodman, Samuel Fankhauser, et
Central Africa; Central America, South America & Caribbean; East Africa; East Asia; South Asia; Southern Africa; West Africa