In the case that impact models are not available, future impacts cannot be projected and analysis needs to focus on current impacts through trend detection and impact attribution or through vulnerability indication. The difference between impact attribution and vulnerability indication methods being that the former require data on observed impacts while the latter are only applied in the absence of such data (Hinkel and Bisaro, 2013a).

When little or no data on impacts is available, then impact analysis cannot be carried further and the identification of vulnerability must rely on vulnerability and capacity indication (see the decision tree on choosing approaches to capacity analysis and the Toolbox section on Vulnerability indication).