Climpag is aimed at bringing together the various aspects and interactions between weather, climate and agriculture in the general context of food security. As per FAO basic texts, the word agriculture includes crops and grasslands, livestock husbandry, forestry and fisheries.
Climpag contains methodologies, tools for a better understanding and analysis of the effect of the variability of weather and climate on agriculture as well as data and maps.

Climate system means the totality of the atmosphere, hydrosphere, biosphere and geosphere and their interactions. Variation in climate is one of the main determinants of agricultural production in all countries.

Climate in a narrow sense is usually defined as the average weather, or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years. These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.

Climate includes seasonal extremes and variations, either locally, regionally, or across the globe. In contrast to weather, climate is generally influenced by slow changes in features like the ocean, the land, the orbit of the Earth around the Sun, and the energy output of the Sun.

Climate variability refers to variations in the mean state and other statistics (such as standard deviations, the occurrence of extremes, etc.) of the climate on all temporal and spatial scales beyond that of individual weather events. Variability may be due to natural internal processes within the climate system (internal variability), or to variations in natural or anthropogenic external forcing (external variability).

Agrometeorology deals with all the weather-sensitive elements of agriculture production. The spectrum of subjects is thus rather wide. It includes pollination, animal migration, human and animal health, transport of pathogens by wind, irrigation, micro-climate manipulation and artificial climates, weather risk assessments, the use of weather forecasts in farming, crop yield and phenology forecasts and particularly advice to farmers. Current agrometeorology relies on a package of new tools, which define modern agrometeorology. They include data acquisition techniques (ground observation, aircraft and satellite), data transmission techniques (including the Internet) and data analysis (models and other software).

At the World Food Summit in Rome (1996) food security was defined as the situation "[…] when all people, at all times, have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life". This definition links the four aspects of food security: availability of staple foods, stability of supplies, access for all to these supplies and the biological utilization of food. Since the 1970s FAO has been active in supporting the establishment, improvement and reinforcement of national food information systems, which are the main structure of food security monitoring. Food Security depends on many factors, but weather variability plays a significant part.