The need for bottom-up assessments of climate risks and adaptation in climate-sensitive regions

Abstract

Studies of climate change at specific intervals of future warming have primarily been addressed through top-down approaches using climate projections and modelled impacts. In contrast, bottom-up approaches focus on the recent past and present vulnerability. Here, we examine climate signals at different increments of warming and consider the need to reconcile top-down and bottom-up approaches. We synthesise insights from recent studies in three climate-sensitive systems where change is a defining feature of the human-environment system. Whilst top-down and bottom-up approaches generate complementary insights into who and what is at risk, integrating their results is a much-needed step towards developing relevant information to address the needs of immediate adaptation decisions. Top-down studies of climate change use climate projections and modelled impacts, whereas bottom-up assessments focus on the recent past and present vulnerability. This Perspective argues that these approaches must be integrated to address the needs of immediate adaptation decisions.