the ipcc estimates the costs of adaptation to be between billion per year chambwera et al however the unep adaptation gap report unep estimates that the costs of adaptation are likely to be twotothree times higher than current global estimates of adaptation costs by and potentially fourtofive times higher than current estimates by the paris agreement notes that the scale of the adaptation challenge and its associated costs are linked to progress on mitigation ie less progress on mitigation will increase the need for and the costs of adaptation while more mitigation will reduce the need to adapt and make adaptation less costly article