Climatology is the scientific study of the earth’s climates including their origin, distribution and role as elements of the natural environment.
The term climatology is derived from two Greek words—klima which means inclination or slope of the earth, and logos which means a discourse.
Climatology is an integral part of physical geography and also a major aspect of meteorology from which it draws its fundamental principles. Critchfield defines climatology as the science that seeks to describe, explain and analyse the nature of climate, how it differs from region to region, and how it influences human activities. “Climatology broadens the findings of meteorology in space and in time to cover the whole earth and periods of time as long as observations and indirect evidence will permit.”
According to Arnold Court this atmospheric science is compounded of parts of three modern disciplines—meteorology, statistics and geography—from which it selects its principles, observations and methods, etc. Thornthwaite says the study of the atmosphere as well as that of the earth’s surface form the core of this discipline since each and every characteristic of climate is determined by the exchange of heat, moisture, and momentum between the earth’s surface and the atmosphere.
Physical climatology, regional (or descriptive) climatology and applied climatology. Physical climatology deals with explaining the factors responsible for bringing about the temporal and spatial variations in heat exchange, moisture exchange and air movement. It is based on the observations of climatic elements such as insolation, duration of sunshine, temperature, air pressure, winds, precipitation, cloudiness, fog, and visibility, etc.
Regional climatology seeks to describe and determine various types of climates by identifying important climatic characteristics and analysing the interaction of the weather and climatic elements upon the life, health and economies of peoples and areas.
Applied climatology deals with the application of the climatological knowledge to specific practical problems in order to improve human living conditions. It seeks to explore the relation of climate to other phenomena and examines climate’s potential effects on human welfare, finally confronting the possibility of modifying climates to meet human needs.
In short, climatology incorporates the study of climatological record, theory of climate, energy and moisture balances of the earth, study of climate as the environment of living organisms, and study of climate as the direct environment of man. Its main aim is to explain the causes of different types of climates, the reasons for their variations, their general and specific locations, their effects on natural vegetation, and the processes that produce different climates.