Studies of climate change vulnerability have been evolving from impact-driven to policy-driven assessments; shifting the focus from estimating expected damages to attempting to reduce them. Impact assessments, exemplified by the Intergovernmental Panel on Climate Change (IPCC) assessment reports, focus primarily on biophysical vulnerability at global and regional scales.
These assessments outline the net impacts of climate change and recommend long-term mitigation targets. More recent vulnerability and adaptation assessments are driven by the need for improved decision analysis at local scales, and focus on vulnerability as a property of coupled social-ecological systems. The goal of these assessments is to identify both the climatic and non-climatic causes of vulnerability and make feasible adaptation recommendations. Top-down impact assessments have been and will continue to be useful for increasing awareness about the projected broad-scale impacts of climate change. However, there is an increasing need for sub-national, bottom-up assessments that provide practical, actionable, policy-relevant recommendations, particularly for the most vulnerable communities in developing countries that are already struggling to adapt to a changing climate.