Asssessing the costs of adaptation to climate change: a review of the UNFCCC and other recent estimates
A re-assessment of the UNFCCC adaptation for climate change 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:
- some sectors have not been included in an assessment of cost (e.g. ecosystems, energy, manufacturing, retailing, and tourism)
- some of those sectors which have been included have been only partially covered
- the additional costs of adaptation have sometimes been calculated as ‘climate mark-ups’ against low levels of assumed investment.
- the potential damages to be avoided by adaptation
- the scarcity of information on adaptation and its cost
- applying a 'climate mark-up' against future investment trends
- investment needed to remove the 'adaptation deficit'
- adaptation costs in a world without an 'adaptation deficit'
- how much impact is being avoided by adaptation?
- the costs of damage not adapted to or 'residual damage'
- how will adaptation costs change over time?
- it is important that robust studies of adaptation cost are, in future, based upon case studies that cover a wide range of places and sectors, and support top-down analyses of the kind evaluated here
- the time period and expected climate changes need specifying (as they were in the UNFCCC study), and results for multiple timeframes would be useful
- non-climate trends need careful portrayal, especially the future levels of non-climate investment
- costs of adapting to varying amounts of impact should be analysed, thus providing a choice range for preparedness to pay
- there needs to be some analysis of the residual impact that adaptation is not likely to avoid, and the resulting damage costs that we need to anticipate.