2.5.1.6. Section 6: Other System Attributes. Optional for an IS-CDD with the exception of consideration should be given to identify the system categorization for information systems and PIT systems as a required capability - the potential impact (low, moderate, or high) resulting from loss of confidentiality, integrity, and availability, if a security breach occurs IAW Reference [10].

For reference or comparison, below is what the JCIDS Manual says for the CDD 2021 itself:

2.5.6.2.4. Natural environmental factors, including climatic design type, terrain, meteorological and oceanographic (METOC) factors, impacts, and effects.