Atmospheric sciences and radiant energy. In contrast to meteorology, which studies short term weather systems lasting up to a few weeks, climatology studies the frequency and trends of those systems. It studies the periodicity of weather events over years to millennia, as well as changes in long-term average weather patterns, in relation to atmospheric conditions. Climatologists, those who practice climatology, study both the nature of climates – local, regional or global – and the natural or human-induced factors that cause climates to change. Climatology considers the past and can help predict future climate change. Phenomena of climatological interest include the atmospheric boundary
Systematics – study of multi-term systems qualitative effects, and the two categories cannot always be separated.) Thus in formal Systematics, Bennettian systems are abstract, and each system represents a qualitative or logical "type" or level analogous to the logical levels used by Bertrand Russell in his Theory of Types. Each formal level consists of qualitatively independent but mutually relevant "terms" that constitute a "universe of discourse" specific to that level, and terminology suitable at one level can cause category confusion when used in other contexts. Every multi-term system so-defined has its special system-level attribute or characteristic emergent quality, such as "dynamism" for the triad, or "significance"